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Johnson CC, Dzewaltowski AC, Dever DE, Krajewski KT, Rai A, Ahamed NU, Allison KF, Flanagan SD, Graham SM, Lovalekar M, Anderst WJ, Connaboy C. Load carriage changes tibiofemoral arthrokinematics during ambulatory tasks in recruit-aged women. Sci Rep 2024; 14:9542. [PMID: 38664550 PMCID: PMC11045865 DOI: 10.1038/s41598-024-60187-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Accepted: 04/19/2024] [Indexed: 04/28/2024] Open
Abstract
The introduction of women into U.S. military ground close combat roles requires research into sex-specific effects of military training and operational activities. Knee osteoarthritis is prevalent among military service members; its progression has been linked to occupational tasks such as load carriage. Analyzing tibiofemoral arthrokinematics during load carriage is important to understand potentially injurious motion and osteoarthritis progression. The study purpose was to identify effects of load carriage on knee arthrokinematics during walking and running in recruit-aged women. Twelve healthy recruit-aged women walked and ran while unloaded (bodyweight [BW]) and carrying additional + 25%BW and + 45%BW. Using dynamic biplane radiography and subject-specific bone models, tibiofemoral arthrokinematics, subchondral joint space and center of closest contact location between subchondral bone surfaces were analyzed over 0-30% stance (separate one-way repeated measures analysis of variance, load by locomotion). While walking, medial compartment contact location was 5% (~ 1.6 mm) more medial for BW than + 45%BW at foot strike (p = 0.03). While running, medial compartment contact location was 4% (~ 1.3 mm) more lateral during BW than + 25%BW at 30% stance (p = 0.04). Internal rotation was greater at + 45%BW compared to + 25%BW (p < 0.01) at 30% stance. Carried load affects tibiofemoral arthrokinematics in recruit-aged women. Prolonged load carriage could increase the risk of degenerative joint injury in physically active women.
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Affiliation(s)
- Camille C Johnson
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, USA
- Orthopaedic Biodynamics Laboratory, Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, PA, USA
| | - Alex C Dzewaltowski
- Center of Lower Extremity Ambulatory Research, Rosalind Franklin University of Medicine & Science, Chicago, IL, USA
| | - Dennis E Dever
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, USA
| | - Kellen T Krajewski
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, USA
| | - Ajinkya Rai
- Orthopaedic Biodynamics Laboratory, Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, PA, USA
| | - Nizam U Ahamed
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, USA
| | - Katelyn F Allison
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, USA
| | - Shawn D Flanagan
- Center of Lower Extremity Ambulatory Research, Rosalind Franklin University of Medicine & Science, Chicago, IL, USA
| | - Scott M Graham
- School of Applied Sciences, Edinburgh Napier University, Edinburgh, Scotland, UK
| | - Mita Lovalekar
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, USA
| | - William J Anderst
- Orthopaedic Biodynamics Laboratory, Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, PA, USA
| | - Chris Connaboy
- Center of Lower Extremity Ambulatory Research, Rosalind Franklin University of Medicine & Science, Chicago, IL, USA.
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Conkright WR, Kargl CK, Hubal MJ, Tiede DR, Beckner ME, Sterczala AJ, Krajewski KT, Martin BJ, Flanagan SD, Greeves JP, O'Leary TJ, Wardle SL, Sahu A, Ambrosio F, Nindl BC. Acute Resistance Exercise Modifies Extracellular Vesicle miRNAs Targeting Anabolic Gene Pathways: A Prospective Cohort Study. Med Sci Sports Exerc 2024:00005768-990000000-00474. [PMID: 38377006 DOI: 10.1249/mss.0000000000003408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2024]
Abstract
BACKGROUND Resistance training confers numerous health benefits that are mediated in part by circulating factors. Towards an enhanced molecular understanding, there is growing interest in a class of signaling biomarkers called extracellular vesicles (EVs). Extracellular vesicles support physiological adaptations to exercise by transporting their cargo (e.g., microRNA [miRNA]) to target cells. Previous studies of changes in EV cargo have focused on aerobic exercise, with limited data examining the effects of resistance exercise. We examined the effect of acute resistance exercise on circulating EV miRNAs and their predicted target pathways. METHODS Ten participants (5 men; age: 26.9 ± 5.5 y, height: 1.7 ± 0.1 m, body mass: 74.0 ± 11.1 kg, body fat: 25.7 ± 11.6 %) completed an acute heavy resistance exercise test (AHRET) consisting of six sets of 10 repetitions of back squats using 75% one-repetition maximum. Pre-/post-AHRET, EVs were isolated from plasma using size exclusion chromatography, and RNA sequencing was performed. Differentially expressed (DE) miRNAs between pre- and post-AHRET EVs were analyzed using Ingenuity Pathway Analysis to predict target messenger RNAs and their target biological pathways. RESULTS Overall, 34 miRNAs were altered by AHRET (p < 0.05), targeting 4,895 mRNAs, with enrichment of 175 canonical pathways (p < 0.01), including 12 related to growth/metabolism (p53, IGF-I, STAT3, PPAR, JAK/STAT, growth hormone, WNT/β-catenin, ERK/MAPK, AMPK, mTOR, and PI3K/AKT) and eight to inflammation signaling (TGF-β, IL-8, IL-7, IL-3, IL-6, IL-2, IL-17, IL-10). CONCLUSIONS Acute resistance exercise alters EV miRNAs targeting pathways involved in growth, metabolism, and immune function. Circulating EVs may serve as significant adaptive signaling molecules influenced by exercise training.
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Affiliation(s)
- William R Conkright
- Neuromuscular Research Lab / Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, PA
| | - Chris K Kargl
- Neuromuscular Research Lab / Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, PA
| | - Monica J Hubal
- Department of Kinesiology, Indiana University-Purdue University Indianapolis, Indianapolis, IN
| | - Dakota R Tiede
- Department of Kinesiology, Indiana University-Purdue University Indianapolis, Indianapolis, IN
| | - Meaghan E Beckner
- Neuromuscular Research Lab / Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, PA
| | - Adam J Sterczala
- Neuromuscular Research Lab / Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, PA
| | - Kellen T Krajewski
- Neuromuscular Research Lab / Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, PA
| | - Brian J Martin
- Neuromuscular Research Lab / Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, PA
| | - Shawn D Flanagan
- Neuromuscular Research Lab / Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, PA
| | | | | | | | | | | | - Bradley C Nindl
- Neuromuscular Research Lab / Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, PA
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Koltun KJ, Sterczala AJ, Sekel NM, Krajewski KT, Martin BJ, Lovalekar M, Connaboy C, Flanagan SD, Wardle SL, O'Leary TJ, Greeves JP, Nindl BC. Effect of acute resistance exercise on bone turnover in young adults before and after concurrent resistance and interval training. Physiol Rep 2024; 12:e15906. [PMID: 38296351 PMCID: PMC10830389 DOI: 10.14814/phy2.15906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 12/11/2023] [Accepted: 12/11/2023] [Indexed: 02/05/2024] Open
Abstract
Weight-bearing physical activity can stimulate bone adaptation. This investigation explored the effect of an acute bout of resistance exercise before and after resistance+interval training on circulating biomarkers of bone metabolism and muscle-bone crosstalk. Healthy young male and female participants (n = 21 male, 28 ± 4 years; n = 17 female, 27 ± 5 years) performed a 6 × 10 squat test (75% 1RM) before and after a 12-week resistance+interval training program. Before and after completion of the training program, blood samples were collected at rest, immediately postexercise, and 2 h postexercise. Blood samples were analyzed for βCTX, P1NP, sclerostin, osteocalcin, IGF-1, and irisin. Significant effects of acute exercise (main effect of time) were observed as increases in concentrations of IGF-1, irisin, osteocalcin, and P1NP from rest to postexercise. A sex*time interaction indicated a greater decline in βCTX concentration from rest to 2 h postexercise and a greater increase in sclerostin concentration from rest to immediately postexercise in male compared with female participants. Sex differences (main effect of sex) were also observed for irisin and P1NP concentrations. In summary, changes in concentrations of biochemical markers of bone metabolism and muscle-bone crosstalk were observed in males and females after an acute bout of resistance exercise and following 12 weeks of resistance+interval training.
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Affiliation(s)
- Kristen J. Koltun
- Department of Sports Medicine and Nutrition, Neuromuscular Research Laboratory/Warrior Human Performance Research CenterUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Adam J. Sterczala
- Department of Sports Medicine and Nutrition, Neuromuscular Research Laboratory/Warrior Human Performance Research CenterUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Nicole M. Sekel
- Department of Sports Medicine and Nutrition, Neuromuscular Research Laboratory/Warrior Human Performance Research CenterUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Kellen T. Krajewski
- Department of Sports Medicine and Nutrition, Neuromuscular Research Laboratory/Warrior Human Performance Research CenterUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Brian J. Martin
- Department of Sports Medicine and Nutrition, Neuromuscular Research Laboratory/Warrior Human Performance Research CenterUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Mita Lovalekar
- Department of Sports Medicine and Nutrition, Neuromuscular Research Laboratory/Warrior Human Performance Research CenterUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Christopher Connaboy
- Department of Sports Medicine and Nutrition, Neuromuscular Research Laboratory/Warrior Human Performance Research CenterUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Shawn D. Flanagan
- Department of Sports Medicine and Nutrition, Neuromuscular Research Laboratory/Warrior Human Performance Research CenterUniversity of PittsburghPittsburghPennsylvaniaUSA
| | | | | | | | - Bradley C. Nindl
- Department of Sports Medicine and Nutrition, Neuromuscular Research Laboratory/Warrior Human Performance Research CenterUniversity of PittsburghPittsburghPennsylvaniaUSA
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Sterczala AJ, Krajewski KT, Peterson PA, Sekel NM, Lovalekar M, Wardle SL, O'Leary TJ, Greeves JP, Flanagan SD, Connaboy C, Nindl BC. Twelve weeks of concurrent resistance and interval training improves military occupational task performance in men and women. Eur J Sport Sci 2023; 23:2411-2424. [PMID: 37517090 DOI: 10.1080/17461391.2023.2239752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/01/2023]
Abstract
In the British Army, ground close combat roles have opened to women, however, they must pass the newly developed, gender-neutral Role Fitness Tests for Soldiers (RFT(S)). Due to physiological differences between sexes, training that optimally prepares both sexes for military occupational demands and the RFT(S) is needed. The purpose of this study was to determine the efficacy of a 12-week periodized strength and power programme with concurrent interval training on RFT(S) performance and determine if performance adaptations differed between sexes. 39 recruit-aged (18-35 yrs) participants, including 21 men (29 ± 1 yrs) and 18 women (27 ± 1 yrs), completed the study. Participants performed 3 training sessions per week that included strength and power resistance training followed by interval training. Pre- to post-training, improvements were observed for seated medicine ball throw (4.5%, p < 0.001), casualty drag (29.8%, p < 0.001), single lift (8.9%, p < 0.001), water can carry (13.8%, p = 0.012), repeated lift and carry (6.5%, p < 0.001), 2-km load carriage (7.2%, p < 0.001) and 2-km run (3.2%, p = 0.021). Pre- to post-training improvements were also observed for maximal squat (27.0%, p < 0.001), bench press (8.9%, p < 0.001) and deadlift (24.6%, p < 0.001) maximal strength, but not upper body power or aerobic capacity. No differences in RFT(S) improvements were observed between sexes, however men performed better than women in all RFT(S) and physical performance measures. Concurrent resistance and interval training improves military occupational performance in men and women; however, women may need more training than men to pass the gender-neutral RFT(S).
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Affiliation(s)
- Adam J Sterczala
- Neuromuscular Research Laboratory and Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, PA, USA
- Human Engineering Research Laboratories, VA Pittsburgh Healthcare System, Pittsburgh, PA, USA
| | - Kellen T Krajewski
- Neuromuscular Research Laboratory and Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, PA, USA
| | - Patrick A Peterson
- Neuromuscular Research Laboratory and Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, PA, USA
| | - Nicole M Sekel
- Neuromuscular Research Laboratory and Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, PA, USA
| | - Mita Lovalekar
- Neuromuscular Research Laboratory and Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, PA, USA
| | - Sophie L Wardle
- Army Health and Performance Research, Army Headquarters, Andover, UK
| | - Thomas J O'Leary
- Army Health and Performance Research, Army Headquarters, Andover, UK
| | - Julie P Greeves
- Army Health and Performance Research, Army Headquarters, Andover, UK
| | - Shawn D Flanagan
- Neuromuscular Research Laboratory and Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, PA, USA
| | - Christopher Connaboy
- Neuromuscular Research Laboratory and Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, PA, USA
| | - Bradley C Nindl
- Neuromuscular Research Laboratory and Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, PA, USA
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Sinnott AM, Kochick VL, Eagle SR, Trbovich AM, Collins MW, Sparto PJ, Flanagan SD, Elbin RJ, Connaboy C, Kontos AP. Comparison of physiological outcomes after dynamic exertion between athletes at return to sport from concussion and controls: Preliminary findings. J Sci Med Sport 2023; 26:682-687. [PMID: 37793956 DOI: 10.1016/j.jsams.2023.09.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 07/20/2023] [Accepted: 09/18/2023] [Indexed: 10/06/2023]
Abstract
OBJECTIVES Compare physiological (heart rate, heart rate variability, and blood pressure), performance (change-of-direction task completion time and errors), and clinical (symptoms and rating of perceived exertion) outcomes during dynamic exertion between athletes at return to sport after concussion to healthy athlete controls. DESIGN Case control. METHODS A sample of 23 (Female = 10; 43.5 %) athletes at medical clearance to play/activity from concussion (CONCUSS) and 23 sex-, age-, and sport-matched healthy athletes (CONTROLS) completed a 5-min seated rest before and after the dynamic exertion test. Independent sample t-tests were used to compare CONCUSS and CONTROLS for completion time, heart rate, and blood pressure; and Mann-Whitney U tests for symptoms, perceived exertion, and errors. A series of ANOVAs were conducted to compare heart rate variability between groups across pre- and post-exercise rest periods. RESULTS There were no differences in heart rate, blood pressure, symptoms, perceived exertion, and errors. CONCUSS were faster on Zig Zag (p = .048) and Pro Agility (p = .018) tasks, reported lower symptom severity (p = .019), and had lower post-EXiT HRV (p < .049) than CONTROLS. CONCLUSIONS Performance, symptoms, perceived exertion, and blood pressure outcomes from dynamic exertion were equivocal between athletes at medical clearance from concussion and healthy controls, which provide empirical support for dynamic exercise to inform medical clearance clinical decision making for sport-related concussion. However, differences in autonomic nervous system functioning indicate that additional research is needed to examine temporal changes in heart rate variability and other physiological outcomes following dynamic exertion.
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Affiliation(s)
- Aaron M Sinnott
- Neuromuscular Research Laboratory-Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, University of Pittsburgh, United States of America; UPMC Sports Medicine Concussion Program, Department of Orthopaedic Surgery, University of Pittsburgh, United States of America; Matthew Gfeller Center, University of North Carolina at Chapel Hill, United States of America. https://twitter.com/AaronSinnottATC
| | - Victoria L Kochick
- Department of Physical Therapy, Slippery Rock University, United States of America; Centers for Rehabilitation Services-Department of Physical Therapy, University of Pittsburgh, United States of America
| | - Shawn R Eagle
- UPMC Sports Medicine Concussion Program, Department of Orthopaedic Surgery, University of Pittsburgh, United States of America; Department of Neurological Surgery, School of Medicine, University of Pittsburgh, United States of America
| | - Alicia M Trbovich
- UPMC Sports Medicine Concussion Program, Department of Orthopaedic Surgery, University of Pittsburgh, United States of America
| | - Michael W Collins
- UPMC Sports Medicine Concussion Program, Department of Orthopaedic Surgery, University of Pittsburgh, United States of America
| | - Patrick J Sparto
- Department of Physical Therapy University of Pittsburgh, United States of America
| | - Shawn D Flanagan
- Neuromuscular Research Laboratory-Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, University of Pittsburgh, United States of America
| | - R J Elbin
- Department of Health, Human Performance and Recreation, University of Arkansas, United States of America
| | - Christopher Connaboy
- Neuromuscular Research Laboratory-Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, University of Pittsburgh, United States of America; Center for Lower Extremity Ambulatory Research Team, Rosalind Franklin University, United States of America
| | - Anthony P Kontos
- UPMC Sports Medicine Concussion Program, Department of Orthopaedic Surgery, University of Pittsburgh, United States of America.
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Krajewski KT, Beethe AZ, Dever DE, Johnson CD, Nindl BC, Lovalekar MT, Flanagan SD, Connaboy C. Hydrodynamic Flow Characteristics of a Recirculating Pool: Examining the Ecological Validity for Training and Testing. J Strength Cond Res 2023; 37:2023-2031. [PMID: 37729515 DOI: 10.1519/jsc.0000000000004500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/22/2023]
Abstract
ABSTRACT Krajewski, KT, Beethe, AZ, Dever, DE, Johnson, CD, Nindl, BC, Lovalekar, MT, Flanagan, SD, and Connaboy, C. Hydrodynamic flow characteristics of a recirculating pool: examining the ecological validity for training and testing. J Strength Cond Res 37(10): 2023-2031, 2023-Recirculating swimming flumes (RSFs) with elliptical multifeature designs have grown in popularity due to their multifunctionality for rehabilitation and training. Because of their smaller footprint, laboratories have adopted their use to investigate swimming and underwater treadmill running. However, little is known about the hydrodynamic characteristics of these RSFs and how they might influence outcomes. The purpose was to determine hydrodynamic flow characteristics of an RSF at the manufacturers' set "speeds" around the centroid of flow projection. Hydrodynamic velocity profiles were collected through a 3D profiling velocimeter, sampling at 200 Hz in an RSF. Data were collected 0.5 and 1.5 m from the projection channel at designated flume "speeds" of 30-95 (+99) in 5-unit increments. Velocity data were collected for 1 minute per trial (location × speed) to determine mean flow velocity (MFV) for 10, 20, 30, and 40 cm2 cross-sectional areas (CSAs). A two-way ANOVA was conducted comparing CSAs from the surface by distance from the current channel (4 × 2). Separate ANOVAs were conducted to assess differences in MFV across each CSA. Significant differences between flow CSAs indicated that MFV is less for a larger area at the same speed, indicative of variable and turbulent flow characteristics across the respective CSAs. Mean flow velocity was further diminished by distance from the flow channel as supported by the main effect, thus exposing an individual to variant flow velocities simultaneously. Limited stability of the flow velocity centroid could affect swim mechanics making the movement pattern no longer analogous to traditional pool and open water swimming, rather resembling swimming upstream in a river with turbulent flow.
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Affiliation(s)
- Kellen T Krajewski
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Anne Z Beethe
- Perception-Action Laboratory, Department of Kinesiology and Health Science, Utah State University, Logan, Utah; and
| | - Dennis E Dever
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Caleb D Johnson
- Spaulding National Running Center, Department of Physical Medicine and Rehabilitation, Harvard Medical School, Cambridge, Massachusetts
| | - Bradley C Nindl
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Mita T Lovalekar
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Shawn D Flanagan
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Chris Connaboy
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania
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Main LC, McLoughlin LT, Flanagan SD, Canino MC, Banks S. Monitoring cognitive function in the fatigued warfighter: A rapid review of cognitive biomarkers. J Sci Med Sport 2023:S1440-2440(23)00079-8. [PMID: 37236820 DOI: 10.1016/j.jsams.2023.04.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Revised: 04/27/2023] [Accepted: 04/27/2023] [Indexed: 05/28/2023]
Abstract
OBJECTIVES Decreases in cognitive function impair occupational performance, reduce occupational safety, and increase musculoskeletal injury risk. The aim of this paper was to identify measures that may be used to monitor cognitive function in the warfighter. DESIGN A rapid review. METHODS A rapid search of Academic Search Complete, MEDLINE, PsycINFO, and SPORTSDiscus databases was conducted. ELIGIBILITY CRITERIA original peer reviewed research articles, written in English, published between 2002 and 2022, and using human participants with no health issues in military training environments or active service. RESULTS Of the 248 articles screened, 58 full-text articles were assessed for eligibility and 29 included in the review. Of these, 16 papers presented data from multi-stressor military training environments, or experimental studies where simulated military tasks were being performed. Thirteen papers focused on an aspect of military work and the implications for cognitive function (i.e., physical load, periods of extended wakefulness or fatigue, and hypoxic conditions). The domains of cognitive function that were assessed (i.e. vigilance, reaction time, working memory, situational awareness, and decision-making) were somewhat consistent among studies. CONCLUSIONS Prolonged exposure to high-stress military environments compromises multiple aspects of cognitive function. These findings highlight the need for a suite of biomarkers to monitor cognitive function and assess the ability of military personnel to attend to and process mission-critical information and make appropriate decisions on the battlefield and other high-stress environments. Our findings suggest that a suite of common tests may provide useful information about cognitive function in the warfighter.
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Affiliation(s)
- Luana C Main
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Australia.
| | - Larisa T McLoughlin
- Behaviour-Brain-Body Research Centre, University of South Australia, Australia.
| | - Shawn D Flanagan
- Neuromuscular Research Laboratory, University of Pittsburgh, United States.
| | - Maria C Canino
- Neuromuscular Research Laboratory, University of Pittsburgh, United States.
| | - Siobhan Banks
- Behaviour-Brain-Body Research Centre, University of South Australia, Australia.
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Krajewski KT, Johnson CC, Ahamed NU, Moir GL, Mi Q, Flanagan SD, Anderst WJ, Connaboy C. Recruit-aged adults may preferentially weight task goals over deleterious cost functions during short duration loaded and imposed gait tasks. Sci Rep 2023; 13:4910. [PMID: 36966216 PMCID: PMC10039906 DOI: 10.1038/s41598-023-31972-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 03/20/2023] [Indexed: 03/27/2023] Open
Abstract
Optimal motor control that is stable and adaptable to perturbation is reflected in the temporal arrangement and regulation of gait variability. Load carriage and forced-marching are common military relevant perturbations to gait that have been implicated in the high incidence of musculoskeletal injuries in military populations. We investigated the interactive effects of load magnitude and locomotion pattern on motor variability, stride regulation and spatiotemporal complexity during gait in recruit-aged adults. We further investigated the influences of sex and task duration. Healthy adults executed trials of running and forced-marching with and without loads at 10% above their gait transition velocity. Spatiotemporal parameters were analyzed using a goal equivalent manifold approach. With load and forced-marching, individuals used a greater array of motor solutions to execute the task goal (maintain velocity). Stride-to-stride regulation became stricter as the task progressed. Participants exhibited optimal spatiotemporal complexity with significant but not meaningful differences between sexes. With the introduction of load carriage and forced-marching, individuals relied on a strategy that maximizes and regulates motor solutions that achieve the task goal of velocity specifically but compete with other task functions. The appended cost penalties may have deleterious effects during prolonged execution, potentially increasing the risk of musculoskeletal injuries.
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Affiliation(s)
- Kellen T Krajewski
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, USA.
| | - Camille C Johnson
- Biodynamics Laboratory, Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, PA, USA
| | - Nizam U Ahamed
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, USA
| | - Gavin L Moir
- Exercise Science Department, East Stroudsburg University, East Stroudsburg, PA, USA
| | - Qi Mi
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, USA
| | - Shawn D Flanagan
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, USA
| | - William J Anderst
- Biodynamics Laboratory, Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, PA, USA
| | - Chris Connaboy
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, USA
- Center for Lower Extremity Ambulatory Research, Rosalind Franklin University of Medicine and Science, North Chicago, IL, USA
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9
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Sekel NM, Beckner ME, Conkright WR, LaGoy AD, Proessl F, Lovalekar M, Martin BJ, Jabloner LR, Beck AL, Eagle SR, Dretsch M, Roma PG, Ferrarelli F, Germain A, Flanagan SD, Connaboy C, Haufler AJ, Nindl BC. Military tactical adaptive decision making during simulated military operational stress is influenced by personality, resilience, aerobic fitness, and neurocognitive function. Front Psychol 2023; 14:1102425. [PMID: 36844343 PMCID: PMC9944034 DOI: 10.3389/fpsyg.2023.1102425] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 01/09/2023] [Indexed: 02/11/2023] Open
Abstract
Laboratory-based studies designed to mimic combat or military field training have consistently demonstrated deleterious effects on warfighter's physical, cognitive, and emotional performance during simulated military operational stress (SMOS). Purpose The present investigation sought to determine the impact of a 48-h simulated military operational stress (SMOS) on military tactical adaptive decision making, and the influence of select psychological, physical performance, cognitive, and physiological outcome measures on decision making performance. Methods Male (n = 48, 26.2 ± 5.5 years, 177.7 ± 6.6 cm, 84.7 ± 14.1 kg.) subjects currently serving in the U.S. military were eligible to participate in this study. Eligible subjects completed a 96-h protocol that occurred over five consecutive days and four nights. Day 2 (D2) and day 3 (D3) consisted of 48-h of SMOS wherein sleep opportunity and caloric needs were reduced to 50%. Differences in SPEAR total block score from baseline to peak stress (D3 minus D1) were calculated to assess change in military tactical adaptive decision making and groups were stratified based on increase (high adaptors) or decrease (low adaptors) of the SPEAR change score. Results Overall, military tactical decision-making declined 1.7% from D1 to D3 (p < 0.001). High adaptors reported significantly higher scores of aerobic capacity (p < 0.001), self-report resilience (p = 0.020), extroversion (p < 0.001), and conscientiousness (p < 0.001). at baseline compared to low adaptors, while low adaptors reported greater scores in Neuroticism (p < 0.001). Conclusion The present findings suggest that service members whose adaptive decision making abilities improved throughout SMOS (i.e., high adaptors) demonstrated better baseline psychological/self-reported resilience and aerobic capacity. Further, changes in adaptive decision-making were distinct from those of lower order cognitive functions throughout SMOS exposure. With the transition of future military conflicts placing higher priority on enhancing and sustaining cognitive readiness and resiliency, data presented here demonstrates the importance of measuring and categorizing baseline measures inherent to military personnel, in order to change and train one's ability to suffer less of a decline during high stress conditions.
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Affiliation(s)
- Nicole M. Sekel
- Neuromuscular Research Laboratory, Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, PA, United States,*Correspondence: Nicole M. Sekel, ✉
| | - Meaghan E. Beckner
- Neuromuscular Research Laboratory, Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, PA, United States
| | - William R. Conkright
- Neuromuscular Research Laboratory, Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, PA, United States
| | - Alice D. LaGoy
- Neuromuscular Research Laboratory, Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, PA, United States,Military Sleep Tactics and Resilience Research Team, Department of Psychiatry, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Felix Proessl
- Neuromuscular Research Laboratory, Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, PA, United States
| | - Mita Lovalekar
- Neuromuscular Research Laboratory, Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, PA, United States
| | - Brian J. Martin
- Neuromuscular Research Laboratory, Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, PA, United States
| | - Leslie R. Jabloner
- Neuromuscular Research Laboratory, Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, PA, United States
| | - Alaska L. Beck
- Neuromuscular Research Laboratory, Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, PA, United States
| | - Shawn R. Eagle
- Neuromuscular Research Laboratory, Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, PA, United States
| | - Michael Dretsch
- U.S. Army Medical Research Directorate-West, Walter Reed Army Institute of Research, Joint Base Lewis-McChord, Washington, WA, United States
| | - Peter G. Roma
- Behavioral Health and Performance Laboratory, Biomedical Research and Environmental Sciences Division, Human Health and Performance Directorate, KBR/NASA Johnson Space Center, Houston, TX, United States,Warfighter Performance Department, Operational Readiness and Health Directorate, Leidos/Naval Health Research Center, San Diego, CA, United States
| | - Fabio Ferrarelli
- Military Sleep Tactics and Resilience Research Team, Department of Psychiatry, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Anne Germain
- Military Sleep Tactics and Resilience Research Team, Department of Psychiatry, School of Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Shawn D. Flanagan
- Neuromuscular Research Laboratory, Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, PA, United States
| | - Christopher Connaboy
- Neuromuscular Research Laboratory, Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, PA, United States
| | - Amy J. Haufler
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD, United States
| | - Bradley C. Nindl
- Neuromuscular Research Laboratory, Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, PA, United States
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LaGoy AD, Conkright WR, Proessl F, Sinnott AM, Beckner ME, Jabloner L, Eagle SR, Sekel NM, Roma PG, Dretsch MN, Flanagan SD, Mi Q, Nindl BC, Germain A, Connaboy C, Ferrarelli F. Less daytime sleepiness and slow wave activity during sleep predict better physical readiness in military personnel. Sleep Health 2023; 9:93-99. [PMID: 36503874 DOI: 10.1016/j.sleh.2022.10.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 10/13/2022] [Accepted: 10/30/2022] [Indexed: 12/14/2022]
Abstract
BACKGROUND Military personnel must maintain physical performance despite exposure to operational stressors such as sleep loss, caloric restriction and high cognitive load. Habitual sleep and specific sleep features are positively associated with fitness and may contribute to physical performance in operational settings. Further, by affecting muscle recovery, sleep may contribute to the ability to maintain performance across multiple days of exposure to operational stressors. OBJECTIVES We examined the role of individual differences in baseline sleep on baseline physical performance and on change in physical performance throughout exposure to simulated military operational stress (SMOS). METHODS Military personnel (36 male, 9 female, 26.3 ± 5.3 years) completed a 5-day SMOS protocol during which they completed a tactical mobility test daily. Sleep questionnaires were administered at intake and sleep was monitored each night with polysomnography. Lasso regressions were used to identify meaningful predictors of physical performance at baseline and of change in physical performance across SMOS. RESULTS Better aerobic fitness, lower daytime sleepiness (Epworth Sleepiness Scale), and lower absolute slow wave activity (0.5-4 Hz) predicted better physical performance at baseline (66.1% of variance explained), but did not relate to changes in performance. CONCLUSIONS Collectively, higher daytime sleepiness and slow wave activity may reflect more chronic exposure to insufficient sleep and higher baseline sleep drive, which in turn led to compromised physical performance. The findings suggest that low self-report sleepiness and low objective slow wave activity may reflect two quantifiable markers of healthy sleep behaviors that have implications for operational performance.
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Affiliation(s)
- Alice D LaGoy
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania, USA; Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - William R Conkright
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Felix Proessl
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Aaron M Sinnott
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Meaghan E Beckner
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Leslie Jabloner
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Shawn R Eagle
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Nicole M Sekel
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Peter G Roma
- Behavioral Health & Performance Laboratory, Biomedical Research and Environmental Sciences Division, Human Health and Performance Directorate, NASA Johnson Space Center/KBR, Houston, Texas, USA
| | - Michael N Dretsch
- U.S. Army Medical Research Directorate-West, Walter Reed Army Institute of Research, Joint Base Lewis-McChord, Washington, USA
| | - Shawn D Flanagan
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Qi Mi
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Bradley C Nindl
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Anne Germain
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Christopher Connaboy
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Fabio Ferrarelli
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.
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11
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Perrey S, Flanagan SD. Editorial: Understanding the effects of transcranial current stimulation on the locomotor and musculoskeletal systems. Front Hum Neurosci 2023; 17:1189405. [PMID: 37113320 PMCID: PMC10126502 DOI: 10.3389/fnhum.2023.1189405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2023] [Accepted: 03/28/2023] [Indexed: 04/29/2023] Open
Affiliation(s)
- Stephane Perrey
- EuroMov Digital Health in Motion, University of Montpellier, IMT Mines Ales, Montpellier, France
- *Correspondence: Stephane Perrey
| | - Shawn D. Flanagan
- Neuromuscular Research Laboratory, University of Pittsburgh, Pittsburgh, PA, United States
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12
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Sinnott AM, Krajewski KT, LaGoy AD, Beckner ME, Proessl F, Canino MC, Nindl BC, Turner RL, Lovalekar MT, Connaboy C, Flanagan SD. Prevention of Lower Extremity Musculoskeletal Injuries in Tactical and First Responder Populations: A Systematic Review and Meta-Analysis of Randomized Trials From 1955 to 2020. J Strength Cond Res 2023; 37:239-252. [PMID: 36026481 DOI: 10.1519/jsc.0000000000004293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
ABSTRACT Sinnott, AM, Krajewski, KT, LaGoy, AD, Beckner, ME, Proessl, F, Canino, MC, Nindl, BC, Turner, RL, Lovalekar, MT, Connaboy, C, and Flanagan, SD. Prevention of lower extremity musculoskeletal injuries in tactical and first responder populations: A systematic review and meta-analysis of randomized trials from 1955 to 2020. J Strength Cond Res 37(1): 239-252, 2023-Lower extremity musculoskeletal injuries (LEMSIs) impose a significant burden on tactical and first responder populations. To determine the effectiveness of LEMSI prevention strategies, we performed a systematic review and meta-analysis of randomized controlled trials published in English from 1955 to 2020 (PROSPERO: CRD42018081799). MEDLINE, EMBASE, Cochrane, CINAHL, ProQuest, and DTIC databases were searched for trials that assigned military service members, police, firefighters, or paramedics to LEMSI prevention interventions with a minimum surveillance period of 12 weeks. Evidence was synthesized as odds ratios (OR) for LEMSI occurrence between individuals assigned to interventions and those assigned to standard activities. Risk of bias was assessed with the Cochrane Risk of Bias tool 2.0. Random-effects meta-analyses were conducted for (a) physical training and (b) footwear modifications to reduce LEMSI and (c) footwear modifications to reduce stress fractures specifically. Certainty in the body of evidence was determined with the GRADE approach. Of 28,499 records, 18 trials comprised of more than 11,000 subjects were synthesized. Interventions included physical training (8, N = 6,838), footwear modifications (8, N = 3,792), nutritional supplementation (1, N = 324), and training modifications (1, N = 350). Overall risk of bias was generally moderate ( N = 7 of 18) or high ( N = 9 of 18). Physical training (OR = 0.87, 95% CI [0.71, 1.08], p = 0.22, I 2 = 58.4%) and footwear modification (OR = 1.13, 95% CI [0.85, 1.49], p = 0.42, I 2 = 0.0%) did not reduce LEMSI or stress fractures (OR = 0.76, 95% CI [0.45, 1.28], p = 0.30, I 2 = 70.7%). Our results indicate that there is weak evidence to support current LEMSI prevention strategies. Future efforts will benefit from longer surveillance periods, assessment of women and nonmilitary populations, improved methodological rigor, and a greater breadth of approaches.
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Affiliation(s)
- Aaron M Sinnott
- Neuromuscular Research Laboratory and Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania; and
| | - Kellen T Krajewski
- Neuromuscular Research Laboratory and Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania; and
| | - Alice D LaGoy
- Neuromuscular Research Laboratory and Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania; and
| | - Meaghan E Beckner
- Neuromuscular Research Laboratory and Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania; and
| | - Felix Proessl
- Neuromuscular Research Laboratory and Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania; and
| | - Maria C Canino
- Neuromuscular Research Laboratory and Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania; and
| | - Bradley C Nindl
- Neuromuscular Research Laboratory and Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania; and
| | - Rose L Turner
- Health Sciences Library System, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Mita T Lovalekar
- Neuromuscular Research Laboratory and Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania; and
| | - Chris Connaboy
- Neuromuscular Research Laboratory and Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania; and
| | - Shawn D Flanagan
- Neuromuscular Research Laboratory and Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania; and
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13
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LaGoy AD, Sinnott AM, Eagle SR, Beckner ME, Conkright WR, Proessl F, Williams J, Dretsch MN, Flanagan SD, Nindl BC, Lovalekar M, Germain A, Ferrarelli F, Connaboy C. Combined effects of time-of-day and simulated military operational stress on perception-action coupling performance. Chronobiol Int 2022; 39:1485-1497. [PMID: 36131615 DOI: 10.1080/07420528.2022.2125405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Perception-action coupling, the ability to 'read and react' to the environment, is essential for military personnel to operate within complex and unpredictable environments. Exposure to military operational stressors (e.g., caloric restriction, sleep loss, physical exertion), including around-the-clock operations, may compromise perception-action coupling, thereby impacting performance and safety. We examined the combined effects of simulated military operational stress (SMOS) and time-of-day on perception-action coupling. Fifty-seven active duty and reservist military personnel (45 M; 26.4 ± 5.6 years) completed a 5-day SMOS protocol that included two consecutive days of caloric restriction, and sleep restriction, and disruption. Participants completed a tablet-based perception-action coupling task (PACT) that involves perceiving whether virtual balls fit through virtual apertures. Familiarization occurred on day 0. Eight trials across day 1 (18:00, 22:00), 2 (04:00, 18:00, 22:00) and 3 (04:00, 18:00, 22:00) were analyzed. Mixed models were run to examine the interactive and main effects of day, and time-of-day on PACT response speed and accuracy outcomes. PACT response speed and accuracy outcomes improved at 18:00 and 22:00, whereas performance at 04:00 deteriorated across days. Perception-action coupling performance was resilient to SMOS, except in the early morning when the circadian drive for sleep is high, and the effects of sleep loss are more prominent.
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Affiliation(s)
- Alice D LaGoy
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.,Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Aaron M Sinnott
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Shawn R Eagle
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Meaghan E Beckner
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - William R Conkright
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Felix Proessl
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Justin Williams
- Sleep and Behavioral Neuroscience Center, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Michael N Dretsch
- US Army Medical Research Directorate-West, Walter Reed Army Institute for Research, Joint Base Lewis-McCord, Washington, USA
| | - Shawn D Flanagan
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Bradley C Nindl
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Mita Lovalekar
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Anne Germain
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Fabio Ferrarelli
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Christopher Connaboy
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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Beckner ME, Conkright WR, Sahu A, Mi Q, Clemens Z, Martin BJ, Flanagan SD, Ferrarelli F, Ambrosio F, Nindl BC. Utility Of Extracellular Vesicles As A Biological Indicator Of Physiological Resilience During Military Operational Stress. Med Sci Sports Exerc 2022. [DOI: 10.1249/01.mss.0000876720.88255.68] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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15
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Canino MC, Proessl F, Hougland JR, Baker JM, Huck DR, Nindl BC, Flanagan SD. Perceived Muscle Soreness Does Not Modulate Corticospinal Excitability. Med Sci Sports Exerc 2022. [DOI: 10.1249/01.mss.0000879324.94019.ff] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Sterczala AJ, Krajewski KT, Peterson PA, Sekel NM, Lovalekar M, Wardle SL, O'Leary TJ, Greeves JP, Flanagan SD, Connaboy C, Nindl BC. Twelve Weeks Of Resistance Training And High Intensity Interval Training Improves Physical Employment Standards Performance. Med Sci Sports Exerc 2022. [DOI: 10.1249/01.mss.0000876740.06435.45] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Sinnott AM, Eagle SR, Kochick V, Collins MW, Trbovich A, Sparto P, Flanagan SD, Elbin RJ, Connaboy C, Kontos AP. Autonomic Nervous System Function After Dynamic Exertion Among Athletes At Medical Clearance Following Concussion. Med Sci Sports Exerc 2022. [DOI: 10.1249/01.mss.0000875820.82380.fe] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Conkright WR, Beckner ME, Sterczala AJ, Mi Q, Lovalekar M, Sahu A, Krajewski K, Martin BJ, Flanagan SD, Greeves JP, O'Leary TJ, Wardle SL, Ambrosio F, Nindl BC. Resistance Exercise Alters Extracellular Vesicle Size And Subpopulation Characteristics Differently In Men And Women. Med Sci Sports Exerc 2022. [DOI: 10.1249/01.mss.0000876236.24292.89] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Peterson PA, Krajewski KT, Sterczala AJ, Mowery DN, Sekel NM, Lovalekar M, Wardle SL, O'Leary TJ, Greeves JP, Flanagan SD, Connaboy C, Nindl BC. 12-weeks Of Resistance Training Elicits Varying Sex Responses In Strength In Military Recruit-aged Adults. Med Sci Sports Exerc 2022. [DOI: 10.1249/01.mss.0000876716.12374.c6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Sekel NM, Conkright WR, Beckner ME, LaGoy AD, Proessl F, Jabloner LR, Beck AL, Eagle S, Lovalekar M, Haufler A, Ferrarelli F, Germain A, Dretsch M, Flanagan SD, Connaboy C, Nindl BC. Slow Wave Activity Sleep Is Significantly Associated With Decision-making During Simulated Military Operational Stress. Med Sci Sports Exerc 2022. [DOI: 10.1249/01.mss.0000877048.43265.89] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Sinnott AM, Eagle SR, Kochick V, Preszler J, Collins MW, Sparto PJ, Flanagan SD, Elbin RJ, Connaboy C, Kontos AP. The Role of Age, Sex, Body Mass Index, and Sport Type on the Dynamic Exertion Test in Healthy Athletes: A Cross-Sectional Study. Clin J Sport Med 2022; 32:e499-e507. [PMID: 35350035 DOI: 10.1097/jsm.0000000000001028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 02/09/2022] [Indexed: 02/04/2023]
Abstract
BACKGROUND The dynamic exertion test (EXiT) was developed to help inform return to play after sport-related concussion, but some factors may threaten the internal validity of EXiT and affect clinical interpretation. OBJECTIVE To compare age, sex, BMI, and sport types across EXiT physiological [pre-EXiT and post-EXiT percentage of maximum heart rate (HR %max) and blood pressure (BP)], performance (change-of-direction task completion time and committed errors), and clinical [symptoms and rating of perceived exertion (RPE)] outcomes among healthy adolescents and adults. STUDY DESIGN Cross-sectional. METHODS Eighty-seven participants ( F = 55, 37.4%) reported symptoms and RPE during the EXiT, which consists of a 12-minute treadmill running protocol, and the dynamic circuit, ball toss, box shuffle (SHUF) and carioca (CAR), zig zag (ZZ), proagility (PA), and arrow agility (AA) tasks. Independent samples t tests were conducted for pre-EXiT and post-EXiT HR %max and BP and change-of-direction task completion time and Mann-Whitney U tests for errors, symptoms, and RPE. A series of 1-way analysis of variance (ANOVAs) and Kruskal-Wallis H tests were conducted to compare collision, contact, and noncontact sport types. RESULTS Adolescents had lower completion time across AA ( P = 0.01) and male athletes lower than female athletes on CAR, ZZ, PA, and AA ( P < 0.04). Male athletes reported greater RPE after the SHUF, CAR, and AA ( P < 0.03). HR %max , errors, and symptoms were equivocal across all subgroups ( P > 0.05). CONCLUSION Age and sex should be considered in the interpretation of performance and clinical, but not physiological, EXiT outcomes. The EXiT is a standardized exercise assessment and generalizable to healthy athletes.
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Affiliation(s)
- Aaron M Sinnott
- Neuromuscular Research Laboratory-Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania
- UPMC Sports Medicine Concussion Program, Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Shawn R Eagle
- UPMC Sports Medicine Concussion Program, Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Victoria Kochick
- Centers for Rehabilitation Services-Department of Physical Therapy, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Jonathan Preszler
- UPMC Sports Medicine Concussion Program, Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Michael W Collins
- UPMC Sports Medicine Concussion Program, Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Patrick J Sparto
- Department of Physical Therapy University of Pittsburgh, Pennsylvania; and
| | - Shawn D Flanagan
- Neuromuscular Research Laboratory-Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Robert J Elbin
- Department of Health, Human Performance and Recreation, University of Arkansas, Fayetteville, Arkansas
| | - Christopher Connaboy
- Neuromuscular Research Laboratory-Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Anthony P Kontos
- UPMC Sports Medicine Concussion Program, Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania
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22
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Conkright WR, Beckner ME, Sterczala AJ, Mi Q, Lovalekar M, Sahu A, Krajewski KT, Martin BJ, Flanagan SD, Greeves JP, O'Leary TJ, Wardle SL, Ambrosio F, Nindl BC. Resistance Exercise Differentially Alters Extracellular Vesicle Size and Subpopulation Characteristics in Healthy Men and Women: An Observational Cohort Study. Physiol Genomics 2022; 54:350-359. [PMID: 35816651 DOI: 10.1152/physiolgenomics.00171.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Extracellular vesicles (EV) are established mediators of adaptation to exercise. Currently, there are no published data comparing changes in EVs between men and women after resistance exercise. PURPOSE We tested the hypothesis that EV profiles would demonstrate a sex-specific signature following resistance exercise. METHODS Ten men and 10 women completed an acute heavy resistance exercise test for back squats using 75% of their one-repetition maximum. Blood was drawn before and immediately after exercise. EVs were isolated from plasma using size exclusion chromatography and stained with antibodies associated with exosomes (CD63), microvesicles (VAMP3), apoptotic bodies (THSD1), and a marker for skeletal muscle EVs (SGCA). RESULTS CD63+ EV concentration and proportion of total EVs increased 23% (p=0.006) and 113% (p=0.005) in both sexes. EV mean size declined in men (p=0.020), but not women, suggesting a relative increase in small EVs in men. VAMP3+ EV concentration and proportion of total EVs increased by 93% (p=0.025) and 61% (p=0.030) in men and women, respectively. SGCA+ EV concentration was 69% higher in women compared to men independent of time (p=0.007). Differences were also observed for CD63, VAMP3, and SGCA median fluorescence intensity, suggesting altered surface protein density according to sex and time. There were no significant effects of time or sex on THSD1+ EVs or fluorescence intensity. CONCLUSION EV profiles, particularly among exosome-associated and muscle-derived EVs, exhibit sex-specific differences in response to resistance exercise which should be further studied to understand their relationship to training adaptations.
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Affiliation(s)
- William R Conkright
- Neuromuscular Research Lab / Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, PA, United States
| | - Meaghan E Beckner
- Neuromuscular Research Lab / Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, PA, United States
| | - Adam J Sterczala
- Neuromuscular Research Lab / Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, PA, United States
| | - Qi Mi
- Neuromuscular Research Lab / Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, PA, United States
| | - Mita Lovalekar
- Neuromuscular Research Lab / Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, PA, United States
| | - Amrita Sahu
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Kellen T Krajewski
- Neuromuscular Research Lab / Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, PA, United States
| | - Brian J Martin
- Neuromuscular Research Lab / Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, PA, United States
| | - Shawn D Flanagan
- Neuromuscular Research Lab / Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, PA, United States
| | - Julie P Greeves
- Army Health and Performance Research, Army Headquarters, Andover, United Kingdom.,Division of Surgery and Interventional Science, University College London, London, United Kingdom.,Norwich Medical School, University of East Anglia, Norwich, United Kingdom
| | - Thomas J O'Leary
- Army Health and Performance Research, Army Headquarters, Andover, United Kingdom.,Division of Surgery and Interventional Science, University College London, London, United Kingdom
| | - Sophie L Wardle
- Army Health and Performance Research, Army Headquarters, Andover, United Kingdom.,Division of Surgery and Interventional Science, University College London, London, United Kingdom
| | - Fabrisia Ambrosio
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, United States.,Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA, United States
| | - Bradley C Nindl
- Neuromuscular Research Lab / Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, PA, United States
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Sterczala AJ, Pierce JR, Barnes BR, Urso ML, Matheny RW, Scofield DE, Flanagan SD, Maresh CM, Zambraski EJ, Kraemer WJ, Nindl BC. Insulin-like growth factor-I biocompartmentalization across blood, interstitial fluid and muscle, before and after 3 months of chronic resistance exercise. J Appl Physiol (1985) 2022; 133:170-182. [PMID: 35678743 DOI: 10.1152/japplphysiol.00592.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This investigation examined the influence of 12-week ballistic resistance training programs on the IGF-I system in circulation, interstitial fluid, and skeletal muscle, at rest and in response to acute exercise. Seventeen college-aged subjects (11 women/6 men; 21.7 ± 3.7 yr) completed an acute ballistic exercise bout before and after the training program. Blood samples were collected pre-, mid-, and postexercise and analyzed for serum total IGF-I, free IGF-I, and IGF binding proteins (IGFBPs) 1-4. Dialysate and interstitial free IGF-I were analyzed in vastus lateralis (VL) interstitial fluid collected pre- and postexercise via microdialysis. Pre- and postexercise VL muscle biopsies were analyzed for IGF-I protein expression, IGF-I receptor phosphorylation (p-IGF-IR), and AKT phosphorylation (p-AKT). Following training, basal serum IGF-I, free IGF-I, IGFBP-2, and IGFBP-3 decreased whereas IGFBP-1 and IGFBP-4 increased. Training reduced basal dialysate and interstitial free IGF-I but had no effect on basal skeletal muscle IGF-I, p-IGF-IR, or p-AKT. Acute exercise elicited transient changes in IGF-I system concentrations and downstream anabolic signaling both pre- and posttraining; training did not affect this acute exercise response. Posttraining, acute exercise-induced changes in dialysate/interstitial free IGF-I were strongly correlated with the changes in intramuscular IGF-I expression, p-IGF-IR, and p-AKT. The divergent influence of resistance training on circulating/interstitial and skeletal muscle IGF-I demonstrates the importance of concurrent, multiple biocompartment analysis when examining the IGF-I system. As training elicited muscle hypertrophy, these findings indicate that IGF-I's anabolic effects on skeletal muscle are mediated by local, rather than systemic mechanisms.NEW & NOTEWORTHY In the first investigation to assess resistance training's effects on the IGF-I system in serum, interstitial fluid, and skeletal muscle, training decreased basal circulating and interstitial IGF-I but did not alter basal intramuscular IGF-I protein activity. Posttraining, acute exercise-induced interstitial IGF-I increases were strongly correlated with intramuscular IGF-I expression and signaling. These findings highlight the importance of multibiocompartment measurement when analyzing IGF-I and suggest that IGF-I's role in hypertrophic adaptations is locally mediated.
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Affiliation(s)
- Adam J Sterczala
- Neuromuscular Research Laboratory/Human Performance Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Joseph R Pierce
- US Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - Brian R Barnes
- US Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - Maria L Urso
- US Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - Ronald W Matheny
- US Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - Dennis E Scofield
- US Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - Shawn D Flanagan
- Neuromuscular Research Laboratory/Human Performance Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Carl M Maresh
- Department of Kinesiology, University of Connecticut, Storrs, Connecticut
| | - Edward J Zambraski
- US Army Research Institute of Environmental Medicine, Natick, Massachusetts
| | - William J Kraemer
- Department of Kinesiology, University of Connecticut, Storrs, Connecticut.,Department of Human Sciences, The Ohio State University, Columbus, Ohio
| | - Bradley C Nindl
- Neuromuscular Research Laboratory/Human Performance Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania.,US Army Research Institute of Environmental Medicine, Natick, Massachusetts
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Beckner ME, Conkright WR, Mi Q, Martin BJ, Sahu A, Flanagan SD, Ledford AK, Wright M, Susmarski A, Ambrosio F, Nindl BC. Neuroendocrine, Inflammatory, and Extracellular Vesicle Responses During the Navy Special Warfare Screener Selection Course. Physiol Genomics 2022; 54:283-295. [PMID: 35695270 PMCID: PMC9291410 DOI: 10.1152/physiolgenomics.00184.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Military operational stress is known to increase adrenal hormones and inflammatory cytokines, while decreasing hormones associated with the anabolic milieu and neuroendocrine system. Less is known about the role of extracellular vesicles (EVs), a form of cell-to-cell communication, in military operational stress and their relationship to circulating hormones. PURPOSE To characterize the neuroendocrine, cytokine, and EV response to an intense, 24-h selection course known as the Naval Special Warfare (NSW) Screener and identify associations between EVs and cytokines. METHODS Blood samples were collected the morning of and following the NSW Screener in 29 men (18 - 26 years). Samples were analyzed for concentrations of cortisol, insulin-like growth factor I (IGF-I), neuropeptide-Y (NPY), brain-derived neurotrophic factor (BDNF), α-klotho, tumor necrosis factor- α (TNFα), and interleukins (IL) -1β, -6, and -10. EVs stained with markers associated with exosomes (CD63), microvesicles (VAMP3), and apoptotic bodies (THSD1) were characterized using imaging flow cytometry and vesicle flow cytometry. RESULTS The selection event induced significant changes in circulating BDNF (-43.2%), IGF-I (-24.56%), TNFα (+17.7%), IL-6 (+13.6%), accompanied by increases in intensities of THSD1+ and VAMP3+ EVs (all p<0.05). Higher concentrations of IL-1β and IL-10 were positively associated with THSD1+ EVs (p<0.05). CONCLUSION Military operational stress altered the EV profile. Surface markers associated with apoptotic bodies were positively correlated with an inflammatory response. Future studies should consider a multi-omics assessment of EV cargo to discern canonical pathways that may be mediated by EVs during military stress.
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Affiliation(s)
- Meaghan E Beckner
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, United States
| | - William R Conkright
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, United States
| | - Qi Mi
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, United States
| | - Brian J Martin
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, United States
| | - Amrita Sahu
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA, United States
| | - Shawn D Flanagan
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, United States
| | - Andrew K Ledford
- Department of Leadership, Ethics, and Law, U.S. Naval Academy, Annapolis, MD, United States
| | - Martin Wright
- Human Performance Lab, Physical Education Department, U.S. Naval Academy, Annapolis, MD, United States
| | - Adam Susmarski
- Brigade Orthopedics and Sports Medicine, U.S. Navy Academy, Annapolis, MD, United States
| | - Fabrisia Ambrosio
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA, United States.,McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, United States
| | - Bradley C Nindl
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, United States
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Sinnott AM, Eagle SR, Kochick V, Bricker IR, Collins MW, Sparto PJ, Flanagan SD, Elbin RJ, Connaboy C, Kontos AP. Test-Retest, Interrater Reliability, and Minimal Detectable Change of the Dynamic Exertion Test (EXiT) for Concussion. Sports Health 2022; 15:410-421. [PMID: 35678147 PMCID: PMC10170234 DOI: 10.1177/19417381221093556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND The Dynamic Exertion Test (EXiT) was developed to inform return-to-play (RTP) decision-making following clinical recovery from sport-related concussion (SRC). The purpose of the current study was to document intrarater and test-retest reliability and minimal detectable change (MDC) scores for physiological [heart rate (HR) and blood pressure], performance (change-of-direction task completion time and errors), and clinical outcomes (endorsed symptoms, perceived exertion) of EXiT, and interrater reliability of performance outcomes. HYPOTHESIS Healthy athletes would exhibit stable physiological responses to the EXiT across visits, demonstrate consistent change-of-direction task completion time between consecutive trials at each visit, and the fastest time (of 2 trials) across visits, and endorse equivocal symptoms and effort across visits. STUDY DESIGN Cross-sectional, test-retest. LEVEL OF EVIDENCE Level 3. METHODS Seventy-nine (female: 34 [43%], 19.6 ± 5.0 years) athletes completed the EXiT at 2 study visits (8.7 ± 4.7 days between visits). Two-way, mixed, intraclass correlation coefficients (ICCs) were used to evaluate intrarater and test-retest reliability. Cronbach's alpha was used to document the internal consistency of symptoms at each visit, and MDC scores were calculated on the physiological, performance, and clinical outcomes. RESULTS Measured and percentage of age-estimated maximum HR were reliable following EXiT (ICC = 0.579-0.618). Change-of-direction task completion time (MDC range = 0.75-8.70 s) had good-to-excellent test-retest (ICC = 0.703-0.948) and interrater (ICC = 0.932-0.965) reliability. Symptoms had a high internal consistency at visits 1 (α = 0.894) and 2 (α = 0.805) and were reliable across visits (ICC = 0.588). CONCLUSION The current investigation established test-retest reliability in addition to MDC scores of an objective dynamic exercise assessment among healthy adolescent and adult athletes. The EXiT may be an objective approach to inform RTP decision-making following SRC recovery. CLINICAL RELEVANCE The EXiT is a clinically feasible exertion-based assessment that can be readily administered in a variety of outpatient clinical settings.
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Conkright WR, Beckner ME, Sahu A, Mi Q, Clemens ZJ, Lovalekar M, Flanagan SD, Martin BJ, Ferrarelli F, Ambrosio F, Nindl BC. Men and women display distinct extracellular vesicle biomarker signatures in response to military operational stress. J Appl Physiol (1985) 2022; 132:1125-1136. [PMID: 35297690 PMCID: PMC9054257 DOI: 10.1152/japplphysiol.00664.2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 03/08/2022] [Accepted: 03/09/2022] [Indexed: 12/14/2022] Open
Abstract
Extracellular vesicles (EVs) are mediators of physiological changes that occur during physical exertion. This study examined the effects of physical exertion with and without sleep and caloric restriction on EV size, concentration, and surface proteins in men and women. Twenty participants (10 men) completed a 5-day simulated military operational stress protocol with daily physical exertion. Blood was drawn before and immediately after exertion at baseline (D1) and following 48-h of sleep and caloric restriction (D3). EV size and concentration were assessed using nanoparticle tracking analysis. EVs were identified with markers associated with exosomes (CD63), microvesicles (VAMP3), apoptotic bodies (THSD1), and skeletal muscle-derived EVs (SGCA) and quantified using imaging flow cytometry. Interactive and main effects of sex, day, and time on EVs were assessed using three-way ANOVAs. EV concentration declined pre to postexertion in women on D1 and D3 but was stable in men. EV size increased from pre to postexertion and from D1 to D3 in men and women. Physical exertion following sleep and caloric restriction increased CD63+ EV concentration, proportion of total EVs, and CD63 surface protein expression regardless of sex. The proportion of SGCA+ EVs increased in men and women following exertion and from D1 to D3 but was higher in women than in men. No differences were observed in VAMP3+ and THSD1+ EVs. This study identified sexually dimorphic EV profiles in response to various stressors. Further investigations are necessary to determine if dimorphic EV responses affect health and performance outcomes during stress.NEW & NOTEWORTHY Sex is understudied in EV research, and most studies limit EV analysis to single stress conditions such as exercise. Multistress conditions consisting of physical exertion and sleep and caloric restriction are common in real-world settings. We demonstrate that physical exertion results in sex-specific EV signatures and that EV profiles vary according to single versus multistress conditions. Our data highlight important biological and ecological characteristics that should be considered in EV research.
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Affiliation(s)
- William R Conkright
- Neuromuscular Research Lab/Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Meaghan E Beckner
- Neuromuscular Research Lab/Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Amrita Sahu
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Qi Mi
- Neuromuscular Research Lab/Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Zachary J Clemens
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Mita Lovalekar
- Neuromuscular Research Lab/Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Shawn D Flanagan
- Neuromuscular Research Lab/Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Brian J Martin
- Neuromuscular Research Lab/Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Fabio Ferrarelli
- School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Fabrisia Ambrosio
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
- Department of Physical Medicine & Rehabilitation, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Bradley C Nindl
- Neuromuscular Research Lab/Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
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Flanagan SD, Dunn-Lewis C, Proessl F, Canino MC, Kraemer WJ. Corticomotor functional indices of traumatic musculoskeletal injury. J Sci Med Sport 2022. [DOI: 10.1016/j.jsams.2021.11.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Beckner ME, Conkright WR, Sahu A, Mi Q, Clemens ZJ, Martin BJ, Flanagan SD, Ferrarelli F, Ambrosio F, Nindl BC. Utility of extracellular vesicles as a potential biological indicator of physiological resilience during military operational stress. Physiol Rep 2022; 10:e15219. [PMID: 35373929 PMCID: PMC8978596 DOI: 10.14814/phy2.15219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Revised: 02/16/2022] [Accepted: 02/17/2022] [Indexed: 12/01/2022] Open
Abstract
Extracellular vesicles (EVs) transport biological content between cells to mediate physiological processes. The association between EVs and resilience, the ability to cope with stress, is unknown. Using unbiased machine learning approaches, we aimed to identify a biological profile of resilience. Twenty servicemen (27.8 ± 5.9 years) completed the Connor Davidson Resilience (CD‐RISC) questionnaire and were exposed to daily physical and cognitive exertion with 48‐hr sleep and caloric restriction. Blood samples from baseline and the second day of stress were analyzed for neuroendocrine biomarkers impacted by military stress. EVs were isolated from plasma and stained with antibodies associated with exosomes (CD63), microvesicles (VAMP3), and apoptotic bodies (THSD1). Individuals were separated into high (n = 10, CD‐RISC > 90) and low (n = 10, CD‐RISC < 79) resilience. EV features were stratified by size, then down‐selected using regression trees and compared between groups. Diagnostic accuracy was assessed using receiver operating characteristic curves. Compared to low resilience, high resilience demonstrated a greater increase in variability of THSD1 local bright spot intensities among large‐sized EVs in response to stress (p = 0.002, Hedges’ g = 1.59). Among medium‐sized EVs, high resilience exhibited a greater decrease in side scatter intensity (p = 0.014, Hedges’ g = 1.17). Both features demonstrated high to moderate diagnostic accuracy for high resilience (AUC = 0.90 and 0.79). In contrast, neuroendocrine biomarker concentrations were similar between groups. The increase in variability among THSD1 + EVs in high, but not low, resilient individuals following stress may suggest high resilience is accompanied by stress‐triggered apoptotic adaptations to the environment that are not detected in neuroendocrine biomarkers.
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Affiliation(s)
- Meaghan E. Beckner
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center Department of Sports Medicine and Nutrition University of Pittsburgh Pittsburgh Pennsylvania USA
| | - William R. Conkright
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center Department of Sports Medicine and Nutrition University of Pittsburgh Pittsburgh Pennsylvania USA
| | - Amrita Sahu
- Department of Physical Medicine & Rehabilitation University of Pittsburgh Pittsburgh Pennsylvania USA
| | - Qi Mi
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center Department of Sports Medicine and Nutrition University of Pittsburgh Pittsburgh Pennsylvania USA
| | - Zachary J. Clemens
- Department of Physical Medicine & Rehabilitation University of Pittsburgh Pittsburgh Pennsylvania USA
| | - Brian J. Martin
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center Department of Sports Medicine and Nutrition University of Pittsburgh Pittsburgh Pennsylvania USA
| | - Shawn D. Flanagan
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center Department of Sports Medicine and Nutrition University of Pittsburgh Pittsburgh Pennsylvania USA
| | - Fabio Ferrarelli
- School of Medicine University of Pittsburgh Pittsburgh Pennsylvania USA
| | - Fabrisia Ambrosio
- Department of Physical Medicine & Rehabilitation University of Pittsburgh Pittsburgh Pennsylvania USA
- McGowan Institute for Regenerative Medicine University of Pittsburgh Pittsburgh Pennsylvania USA
| | - Bradley C. Nindl
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center Department of Sports Medicine and Nutrition University of Pittsburgh Pittsburgh Pennsylvania USA
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Beethe AZ, Flanagan SD, Lovalekar M, Fisher LE, Nindl BC, Connaboy C. The Bilateral Deficit Phenomenon in Elbow Flexion: Explanations for Its Inconsistent Occurrence and Detection. Percept Mot Skills 2021; 129:47-62. [PMID: 34913749 DOI: 10.1177/00315125211060953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The underlying mechanism(s) of the Bilateral Deficit (BLD) phenomenon is without consensus. Methodological inconsistencies across prior works may be an important source of equivocal results and interpretations. Based on repeatability problems with the BLD measure and maximal force definition, the presence or absence of the BLD phenomenon is altered, shifting conclusions of its mechanistic cause. Our purpose in this study was to examine methodological inconsistencies in applying the BLD measure to establish optimal methods for evaluating the underlying mechanism. Eleven healthy participants engaged in one familiarity and five test sessions, completing bilateral and unilateral elbow maximal voluntary isometric contractions. We defined maximal force by averaged and absolute peak and plateau values. BLD was evident if the bilateral index (BI), the ratio of the bilateral over summed unilateral forces, was statistically different from zero. We addressed interclass correlations (ICC), Chronbach's α, standard error of the mean, and minimal detectable change between and within sessions for all force measures and BI. We evaluated all combinations of sessions (i.e., 1-2, 3-5, 5-6) and maximal forces to establish the optimal number of sessions to achieve reliability. BLD was present for test sessions, but not for familiarization. All measures of maximal force were highly reliable between and within sessions (ICC(2,1) ≥ .895). BI was only considered significantly reliable in sessions 3-5 (p < .027), defined by absolute and average plateau forces, but reliability was still quantifiably poor (absolute: ICC(2,1) = .392; average: ICC(2,1) = .375). These results demonstrate that high force reliability within and between sessions does not translate to stable and reliable BI, potentially exposing the lack of any defined BLD mechanism.
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Affiliation(s)
- Anne Z Beethe
- Neuromuscular Research Laboratory and Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, 6614University of Pittsburgh, Pittsburgh, PA, USA.,Perception Action Laboratory, Department of Kinesiology and Health Science, Utah State University, Logan, UT, USA
| | - Shawn D Flanagan
- Neuromuscular Research Laboratory and Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, 6614University of Pittsburgh, Pittsburgh, PA, USA
| | - Mita Lovalekar
- Neuromuscular Research Laboratory and Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, 6614University of Pittsburgh, Pittsburgh, PA, USA
| | - Lee E Fisher
- Rehab Neural Engineering Laboratories, Department of Physical Medicine and Rehabilitation, 6614University of Pittsburgh, Pittsburgh, PA, USA
| | - Bradley C Nindl
- Neuromuscular Research Laboratory and Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, 6614University of Pittsburgh, Pittsburgh, PA, USA
| | - Christopher Connaboy
- Neuromuscular Research Laboratory and Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, 6614University of Pittsburgh, Pittsburgh, PA, USA
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Eagle SR, Collins MW, Dretsch MN, Uomoto JM, Connaboy C, Flanagan SD, Kontos AP. Network Analysis of Research on Mild Traumatic Brain Injury in US Military Service Members and Veterans During the Past Decade (2010-2019). J Head Trauma Rehabil 2021; 36:E345-E354. [PMID: 33741827 DOI: 10.1097/htr.0000000000000675] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To evaluate trends in the extant literature on mild traumatic brain injury (mTBI) in military service members and veterans using network analysis based on a comprehensive search of original, peer-reviewed research articles involving human participants published between January 1, 2010, and December 31, 2019. Specifically, we employed network analysis to evaluate associations in the following areas: (1) peer-reviewed journals, (2) authors, (3) organizations/institutions, and (4) relevant key words. PARTICIPANTS Included studies were published in peer-reviewed journals available on Web of Science database, using US military service members or veterans. DESIGN Bibliometric network analytical review. MAIN MEASURES Outcomes for each analysis included number of articles, citations, total link strength, and clusters. RESULTS The top publishing journals were (1) Journal of Head Trauma and Rehabilitation, (2) Military Medicine, (3) Brain Injury, (4) Journal of Neurotrauma, and (5) Journal of Rehabilitation Research and Development. The top publishing authors were (1) French, (2) Lange, (3) Cooper, (4) Vanderploeg, and (5) Brickell. The top research institutions were (1) Defense and Veterans Brain Injury Center, (2) Uniformed Services University of the Health Sciences, (3) University of California San Diego, (4) Walter Reed National Military Medical Center, and (5) Boston University. The top co-occurring key words in this analysis were (1) posttraumatic stress disorder (PTSD), (2) persistent postconcussion symptoms (PPCS), (3) blast injury, (4) postconcussion syndrome (PCS), and (5) Alzheimer's disease. CONCLUSIONS The results of this network analysis indicate a clear focus on veteran health, as well as investigations on chronic effects of mTBI. Research in civilian mTBI indicates that delaying treatment for symptoms and impairments related to mTBI may not be the most precise treatment strategy. Increasing the number of early, active, and targeted treatment trials in military personnel could translate to meaningful improvements in clinical practices for managing mTBI in this population.
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Affiliation(s)
- Shawn R Eagle
- Departments of Orthopaedic Surgery (Drs Eagle, Collins, and Kontos) and Sports Medicine and Nutrition (Drs Connaboy and Flanagan), University of Pittsburgh, Pittsburgh, Pennsylvania; UPMC Sports Medicine Concussion Program, Pittsburgh, Pennsylvania (Drs Collins and Kontos); US Army Medical Research Directorate-West, Walter Reed Army Institute of Research, Joint Base Lewis-McChord, Washington (Dr Dretsch); and VA Puget Sound Health Care System-American Lake Division, Tacoma, Washington (Dr Uomoto)
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LaGoy AD, Cashmere JD, Beckner ME, Eagle SR, Sinnott AM, Conkright WR, Miller E, Derrow C, Dretsch MN, Flanagan SD, Nindl BC, Connaboy C, Germain A, Ferrarelli F. A trait of mind: stability and robustness of sleep across sleep opportunity manipulations during simulated military operational stress. Sleep 2021; 45:6357670. [PMID: 34432067 DOI: 10.1093/sleep/zsab219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 08/17/2021] [Indexed: 11/14/2022] Open
Abstract
STUDY OBJECTIVES Within-subject stability of certain sleep features across multiple nights is thought to reflect the trait-like behavior of sleep. However, to be considered a trait, a parameter must be both stable and robust. Here, we examined the stability (i.e., across the same sleep opportunity periods) and robustness (i.e., across sleep opportunity periods that varied in duration and timing) of different sleep parameters. METHODS Sixty-eight military personnel (14 W) spent 5 nights in the sleep laboratory during a simulated military operational stress protocol. After an adaptation night, participants had an 8-hour sleep opportunity (23:00-07:00) followed by 2 consecutive nights of sleep restriction and disruption which included two 2-hour sleep opportunities (01:00-03:00; 05:00-07:00) and, lastly, another 8-hour sleep opportunity (23:00-07:00). Intra-class correlation coefficients were calculated to examine differences in stability and robustness across different sleep parameters. RESULTS Sleep architecture parameters were less stable and robust than absolute and relative spectral activity parameters. Further, relative spectral activity parameters were less robust than absolute spectral activity. Absolute alpha and sigma activity demonstrated the highest levels of stability that were also robust across sleep opportunities of varying duration and timing. CONCLUSIONS Stability and robustness varied across different sleep parameters, but absolute NREM alpha and sigma activity demonstrated robust trait-like behavior across variable sleep opportunities. Reduced stability of other sleep architecture and spectral parameters during shorter sleep episodes as well as across different sleep opportunities has important implications for study design and interpretation.
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Affiliation(s)
- Alice D LaGoy
- University of Pittsburgh, Pittsburgh, PA, USA.,University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | | | | | | | | | | | - Eric Miller
- University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Carson Derrow
- University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Michael N Dretsch
- US Army Medical Research Directorate-West, Walter Reed Army Institute of Research, Joint Base Lewis-McChord, WA, USA
| | | | | | | | - Anne Germain
- University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Fabio Ferrarelli
- University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
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Bird MB, Conkright WR, Lovalekar M, Beckner ME, Sekel NM, Doyle TL, Flanagan SD, Connaboy C, Martin BJ, Nindl BC. Higher Baseline Aerobic Fitness Influences Jumping Performance During Military Operational Stress. Med Sci Sports Exerc 2021. [DOI: 10.1249/01.mss.0000759684.09759.35] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Beck AL, Prossel F, Canino M, Beckner ME, Sterczala AJ, Dunn-Lewis C, Conkright WR, Sinnott AM, LaGoy A, Eagle SR, Ferrarelli F, Germain A, Connaboy C, Nindl BC, Flanagan SD. Similar Corticospinal Excitability In Military Men And Women During Simulated Operational Stress. Med Sci Sports Exerc 2021. [DOI: 10.1249/01.mss.0000763084.82590.54] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Beckner ME, Conkright WR, Eagle SR, Martin BJ, Sinnott AM, LaGoy AD, Proessl F, Lovalekar M, Jabloner L, Roma PG, Basner M, Ferrarelli F, Germain A, Flanagan SD, Connaboy C, Nindl BC. Impact Of Simulated Operational Stress On Cognition Relative To Resilience, Fitness, Vigilance, And Neuroendocrine Biomarkers. Med Sci Sports Exerc 2021. [DOI: 10.1249/01.mss.0000763368.65135.e0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Canino MC, Proessl F, Beck AL, Dunn-Lewis C, Kraemer WJ, Flanagan SD. Sensorimotor Cortical Thickness Moderates Corticospinal Excitability. Med Sci Sports Exerc 2021. [DOI: 10.1249/01.mss.0000762944.36604.16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Conkright WR, Beckner ME, Sahu A, Clemens ZJ, Lovalekar M, Mi Q, Martin BJ, Flanagan SD, Ambrosio F, Nindl BC. Extracellular Vesicle Concentration But Not Size Differs Between Men And Women During Military Operational Stress. Med Sci Sports Exerc 2021. [DOI: 10.1249/01.mss.0000763532.42320.15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Proessl F, Canino MC, Beckner ME, Conkright WR, Sinnott AM, Eagle SR, LaGoy AD, Beck AL, Sterczala AJ, Connaboy C, Ferrarelli F, Germain A, Nindl BC, Flanagan SD. Corticospinal Excitability And Resilience During Simulated Military Operational Stress. Med Sci Sports Exerc 2021. [DOI: 10.1249/01.mss.0000763112.93759.4a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Jabloner LR, Beckner ME, Conkright WR, Lagoy AD, Lovalekar M, Sinnott AM, Proessl F, Martin BJ, Lieberman HR, Ferrarelli F, Germain A, Flanagan SD, Connaboy C, Nindl BC. Impact Of Higher Aerobic Fitness On Neurocognitive Function During Simulated Military Operational Stress. Med Sci Sports Exerc 2021. [DOI: 10.1249/01.mss.0000763184.32456.87] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Sterczala AJ, Krajewski KT, Sekel NM, Martin BJ, Greeves JP, O'Leary TJ, Wardle SL, Van Eck C, Flanagan SD, Connaboy C, Nindl BC. Relationship Between Bone Mineral Density And Irisin, At Rest And In Response To Exercise. Med Sci Sports Exerc 2021. [DOI: 10.1249/01.mss.0000760472.10797.67] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Beethe AZ, Ahamed NU, Connaboy C, Lovalekar M, Fisher LE, Nindl BC, Flanagan SD. Differences in compound muscle activation patterns explain upper extremity bilateral deficits. Hum Mov Sci 2021; 79:102851. [PMID: 34333306 DOI: 10.1016/j.humov.2021.102851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 06/20/2021] [Accepted: 07/21/2021] [Indexed: 10/20/2022]
Affiliation(s)
- Anne Z Beethe
- Neuromuscular Research Laboratory and Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, PA, United States of America; Perception Action Laboratory, Department of Kinesiology and Health Science, Utah State University, Logan, UT, United States of America.
| | - Nizam U Ahamed
- Neuromuscular Research Laboratory and Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Christopher Connaboy
- Neuromuscular Research Laboratory and Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Mita Lovalekar
- Neuromuscular Research Laboratory and Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Lee E Fisher
- Rehab Neural Engineering Laboratories, Department of Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Bradley C Nindl
- Neuromuscular Research Laboratory and Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, PA, United States of America
| | - Shawn D Flanagan
- Neuromuscular Research Laboratory and Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, PA, United States of America
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Krajewski KT, Allen IT, Johnson CC, Dever DE, Ahamed NU, Flanagan SD, Mi Q, Anderst WJ, Connaboy C. Loaded forced-marching shifts mechanical contributions proximally and disrupts stride-to-stride joint work modulation in recruit aged women. Gait Posture 2021; 88:22-27. [PMID: 33957553 DOI: 10.1016/j.gaitpost.2021.04.040] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2021] [Revised: 04/20/2021] [Accepted: 04/22/2021] [Indexed: 02/02/2023]
Abstract
BACKGROUND Military personnel in combat roles often perform gait tasks with additional load, which can affect the contributions of joint mechanical work (positive and negative). Furthermore, different locomotion patterns can also affect joint specific work contributions. While mean behavior of joint work is important to understanding gait, changes in joint kinetic modulation, or the regulation/control of stride-to-stride joint work variability is necessary to elucidate locomotor system function. Suboptimal modulation exhibited as a stochastic time-series (large fluctuation followed by an opposite smaller fluctuation) could potentially affect locomotion efficiency and portend injury risk. It remains unclear how the locomotor system responds to a combination of load perturbations and varying locomotion patterns. RESEARCH QUESTION What are the interactive effects of load magnitude and locomotion pattern on joint positive/negative work and joint work modulation in healthy, active, recruit-aged women? METHODS Eleven healthy, active, recruit-aged (18-33 years) women ran and forced-marched (walking at a velocity an individual would typically jog) in bodyweight (BW), an additional 25 % of BW (+25 %BW) and an additional 45 % of BW (+45 %BW) conditions at a velocity above their gait transition velocity. Joint work was calculated as the time integral of joint power. Joint work modulation was assessed with detrended fluctuation analysis (DFA) on consecutive joint work time-series. RESULTS Joint work contributions shifted proximally for forced-marching demonstrated by lesser (p < .001) positive/negative ankle work but greater (p = .001) positive hip work contributions compared to running. Running exhibited optimal positive ankle work modulation compared to forced-marching (p = .040). Knee and ankle negative joint work modulation was adversely impacted compared to the hip during forced-marching (p < .001). SIGNIFICANCE Employing forced-marching gait while under loads of 25 and 45 % of BW reduces the ability of the plantar-flexors and knee extensors to optimally contribute to energy absorption and propulsion in recruit-aged women, potentially reducing metabolic efficiency and increasing injury risk.
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Affiliation(s)
- Kellen T Krajewski
- Neuromuscular Research Laboratory, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, USA.
| | - Ian T Allen
- Neuromuscular Research Laboratory, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, USA
| | - Camille C Johnson
- Biodynamics Laboratory, Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, PA, USA
| | - Dennis E Dever
- Neuromuscular Research Laboratory, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, USA
| | - Nizam U Ahamed
- Neuromuscular Research Laboratory, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, USA
| | - Shawn D Flanagan
- Neuromuscular Research Laboratory, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, USA
| | - Qi Mi
- Neuromuscular Research Laboratory, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, USA
| | - William J Anderst
- Biodynamics Laboratory, Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, PA, USA
| | - Chris Connaboy
- Neuromuscular Research Laboratory, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, USA
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Conkright WR, Beckner ME, Sinnott AM, Eagle SR, Martin BJ, Lagoy AD, Proessl F, Lovalekar M, Doyle TLA, Agostinelli P, Sekel NM, Flanagan SD, Germain A, Connaboy C, Nindl BC. Neuromuscular Performance and Hormonal Responses to Military Operational Stress in Men and Women. J Strength Cond Res 2021; 35:1296-1305. [PMID: 33780395 DOI: 10.1519/jsc.0000000000004013] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Abstract
Conkright, WR, Beckner, ME, Sinnott, AM, Eagle, SR, Martin, BJ, Lagoy, AD, Proessl, F, Lovalekar, M, Doyle, TLA, Agostinelli, P, Sekel, NM, Flanagan, SD, Germain, A, Connaboy, C, and Nindl, BC. Neuromuscular performance and hormonal responses to military operational stress in men and women. J Strength Cond Res 35(5): 1296–1305, 2021—Women have recently been integrated into ground close combat positions; however, there are limited data in women in these roles. We aimed to test the hypothesis that there would be no sex-specific neuromuscular responses, but hormonal signaling would be differentially impacted when exposed to simulated military operational stress (SMOS). Neuromuscular performance was assessed daily using a tactical mobility test (TMT) in 54 male and 15 female military members. Blood was drawn before/after TMT. Mood states were assessed each morning. Unloaded 300-m shuttle time increased 6% in both sexes and remained 7% higher after 1 day of recovery compared with baseline (p < 0.05 for both), whereas performance was maintained in other TMT events (p > 0.05). Growth hormone increased in men, but not women, before to after TMT (p < 0.001 vs. p = 0.086). Women experienced a greater decline in insulin-like growth factor-I across days compared with men (
= 0.778 vs. 0.209, respectively, p < 0.001). Brain-derived neurotrophic factor increased significantly in men only from before to after TMT on day 1 (men: +107% vs. women: +10%) but no difference on days 3 or 4. Cortisol increased 69% from before to after TMT when averaged by sex and day. Negative mood states (depression, tension, and anger) and altered hormonal concentrations were associated with poorer TMT performance. Acute SMOS differentially impacted circulating hormonal milieu in men and women, but no differences in physical performance responses. Unloaded 300-m shuttle was negatively impacted while other fitness domains were maintained. Relationships between performance and mood/endocrine signaling highlight the potential for self-report measures and biomarkers to serve as indicators of performance change.
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Affiliation(s)
- William R Conkright
- Department of Sports Medicine and Nutrition, Neuromuscular Research Laboratory/Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Meaghan E Beckner
- Department of Sports Medicine and Nutrition, Neuromuscular Research Laboratory/Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Aaron M Sinnott
- Department of Sports Medicine and Nutrition, Neuromuscular Research Laboratory/Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Shawn R Eagle
- Department of Sports Medicine and Nutrition, Neuromuscular Research Laboratory/Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Brian J Martin
- Department of Sports Medicine and Nutrition, Neuromuscular Research Laboratory/Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Alice D Lagoy
- Department of Sports Medicine and Nutrition, Neuromuscular Research Laboratory/Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
- Department of Psychiatry, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania; and
| | - Felix Proessl
- Department of Sports Medicine and Nutrition, Neuromuscular Research Laboratory/Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Mita Lovalekar
- Department of Sports Medicine and Nutrition, Neuromuscular Research Laboratory/Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Tim L A Doyle
- Faculty of Medicine, Health, and Human Sciences, Macquarie University, Sydney, Australia
| | - Phil Agostinelli
- Department of Sports Medicine and Nutrition, Neuromuscular Research Laboratory/Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Nicole M Sekel
- Department of Sports Medicine and Nutrition, Neuromuscular Research Laboratory/Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Shawn D Flanagan
- Department of Sports Medicine and Nutrition, Neuromuscular Research Laboratory/Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Anne Germain
- Department of Psychiatry, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania; and
| | - Christopher Connaboy
- Department of Sports Medicine and Nutrition, Neuromuscular Research Laboratory/Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Bradley C Nindl
- Department of Sports Medicine and Nutrition, Neuromuscular Research Laboratory/Warrior Human Performance Research Center, University of Pittsburgh, Pittsburgh, Pennsylvania
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Beckner ME, Conkright WR, Eagle SR, Martin BJ, Sinnott AM, LaGoy AD, Proessl F, Lovalekar M, Jabloner LR, Roma PG, Basner M, Ferrarelli F, Germain A, Flanagan SD, Connaboy C, Nindl BC. Impact of simulated military operational stress on executive function relative to trait resilience, aerobic fitness, and neuroendocrine biomarkers. Physiol Behav 2021; 236:113413. [PMID: 33811909 DOI: 10.1016/j.physbeh.2021.113413] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 03/11/2021] [Accepted: 03/29/2021] [Indexed: 01/06/2023]
Abstract
PURPOSE To study the impact of 48 h of simulated military operational stress (SMOS) on executive function, in addition to the role of trait resilience (RES) and aerobic fitness (FIT) on executive function performance. Associations between executive function and neuropeptide-Y (NPY), brain-derived neurotropic factor (BDNF), insulin-like growth factor-I (IGF-I), oxytocin, and α-klotho (klotho) were assessed to elucidate potential biomarkers that may contribute to cognitive performance during a multi-factorial stress scenario. METHODS Fifty-four service members (SM) (26.4 ± 5.4 years, 178.0 ± 6.5 cm, 85.2 ± 14.0 kg) completed the 5-day protocol, including daily physical exertion and 48 h of restricted sleep and caloric intake. Each morning subjects completed a fasted blood draw followed by Cognition, a 10-part cognitive test battery assessing executive function. SMs were grouped into tertiles [low (L-), moderate (M-), high (H-)] based on Connor Davidson Resilience Score (RES) and V˙O2peak (FIT). Repeated measures ANOVA were run to analyze the effect of day on cognitive performance and biomarker concentration. Separate two-way mixed ANOVAs were run to determine the interaction of group by day on cognitive function. Friedman test with Bonferroni-corrected pairwise comparisons were used if assumptions for ANOVA were not met. Associations between changes in biomarkers and cognitive performance were analyzed using parametric and non-parametric correlation coefficients. RESULTS SMOS reduced SM vigilance -11.3% (p < 0.001) and working memory -5.6% (p = 0.015), and increased risk propensity +9.5% (p = 0.005). H-RES and H-FIT SMs demonstrated stable vigilance across SMOS (p > 0.05). Vigilance was compromised during SMOS in L- and M-RES (p = 0.007 and p = 0.001, respectively) as well as L- and M-FIT (p = 0.001 and p = 0.031, respectively). SMOS reduced circulating concentrations of α-klotho -7.2% (p = 0.004), NPY -6.4% (p = 0.001), and IGF-I -8.1% (p < 0.001) from baseline through the end of the protocol. BDNF declined -19.2% after the onset of sleep and caloric restriction (p = 0.005) with subsequent recovery within 48 h. Oxytocin remained stable (p > 0.05). Several modest associations between neuroendocrine biomarkers and cognitive performance were identified. CONCLUSION This study demonstrates H-FIT and H-RES may buffer the impact of SMOS on vigilance. SMOS negatively impacted circulating neuroendocrine biomarkers. While BDNF returned to baseline concentrations by the end of the 5 d protocol, NPY, IGF-I, and α-klotho may require a longer recovery period. These data suggest that the military may benefit by training and/or selection processes targeting at augmenting trait resilience and aerobic fitness for increased readiness.
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Affiliation(s)
- Meaghan E Beckner
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, USA.
| | - William R Conkright
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, USA
| | - Shawn R Eagle
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, USA
| | - Brian J Martin
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, USA
| | - Aaron M Sinnott
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, USA
| | - Alice D LaGoy
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, USA; Military Sleep Tactics and Resilience Research Team, Department of Psychiatry, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Felix Proessl
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, USA
| | - Mita Lovalekar
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, USA
| | - Leslie R Jabloner
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, USA
| | - Peter G Roma
- Behavioral Health & Performance Laboratory, Biomedical Research and Environmental Sciences Division, KBR/NASA Johnson Space Center, Houston, TX, USA
| | - Mathias Basner
- Division of Sleep and Chronobiology, Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Fabio Ferrarelli
- Military Sleep Tactics and Resilience Research Team, Department of Psychiatry, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Anne Germain
- Military Sleep Tactics and Resilience Research Team, Department of Psychiatry, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Shawn D Flanagan
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, USA
| | - Christopher Connaboy
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, USA
| | - Bradley C Nindl
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, USA
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Dunn-Lewis C, Dell'aquila MP, Flanagan SD. Men and women trainers equally effective at promoting exercise adherence, self-efficacy, and fitness in women. J Sports Med Phys Fitness 2021; 62:47-50. [PMID: 33666072 DOI: 10.23736/s0022-4707.21.10575-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND This study examined the effect of a personal trainer's sex on self-efficacy and fitness in woman clients. METHODS Women (n: 28; mean ± SD; age, 41.6 ± 15.0 yrs.; height, 153.49 ± 28.11cm; BMI, 25.9 ± 6.4 kg•m-2) completed a perceptual scale of self-efficacy (BARSE) and fitness tests before and after a training program. Trainers (men and women) met one-on-one with the volunteers on a biweekly basis for 8 weeks. Univariate analyses of change scores and repeated measures analysis of variance with Fisher's LSD pairwise comparisons tested changes in dependent variables by trainer sex. RESULTS Significant increases were seen in (mean ± SE; change for men trainers; change for woman trainers): self-efficacy (7.3 ± 3.4; 7.3 ± 2.7%); leg press strength (18.2 ± 3.7; 16.4 ± 3.3 kg); seated row (6.1 ± 1.5; 5.3 ± 1.3 kg); muscular endurance in 60° flexion hold (20.5 ± 5.8; 24.8 ± 5.0 sec) and wall-sit (19.9 ± 6.4; 33.5 ± 5.8 sec); but not flexibility (V-sit, 7.11 ± 5.51; 4.23 ± 4.50 cm). Chest press strength significantly increased for women trainers only (2.7 ± 2.2; 5.3 ± 1.8 kg). Despite this, there were no significant differences for any variable in the change from pre-to-post based on the sex of the trainer. CONCLUSIONS Both men and woman-led training was effective for increasing markers of self-efficacy and fitness in woman clients.
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Affiliation(s)
- Courtenay Dunn-Lewis
- Department of Cardiothoracic Surgery, University of Pittsburgh, Pittsburgh PA, USA -
| | | | - Shawn D Flanagan
- Neuromuscular Research Laboratory, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, USA
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Proessl F, Beckner ME, Sinnott AM, Eagle SR, LaGoy AD, Conkright WR, Canino MC, Sterczala AJ, Midhe Ramkumar PP, Sciavolino BM, Connaboy C, Ferrarelli F, Germain A, Nindl BC, Flanagan SD. Reliability of corticospinal excitability estimates for the vastus lateralis: Practical considerations for lower limb TMS task selection. Brain Res 2021; 1761:147395. [PMID: 33662340 DOI: 10.1016/j.brainres.2021.147395] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 02/14/2021] [Accepted: 02/16/2021] [Indexed: 11/29/2022]
Abstract
Transcranial magnetic stimulation (TMS) is increasingly used to examine lower extremity corticospinal excitability (CSE) in clinical and sports research. Because CSE is task-specific, there is growing emphasis on the use of ecological tasks. Nevertheless, the comparative reliability of CSE measurements during established (e.g. knee extensions; KE) and more recent ecological (e.g. squats; SQT) lower extremity tasks has received less attention. The aim of this study was to compare the test-retest reliability of CSE, force, and muscle activity (EMG) during isometric SQT and KE. 19 right-footed men (age: 25 ± 5 yrs) with similar fitness and body composition performed SQT (N = 7) or KE (N = 12) on two consecutive days. Force and EMG were recorded during maximum voluntary isometric contractions (MVC). Corticospinal excitability was determined in the dominant leg during light (15% MVC) contractions based on motor evoked potential (MEP) stimulus-response-curves (SRC). Test-retest reliability, absolute agreement, and consistency were determined for force, EMG, and SRC MEP maximum (MEPMAX) and rising phase midpoint (V50). As a secondary analysis, all outcomes were compared between groups with mixed-methods ANCOVAs (Task × Time, covariate: body-fat-percentage). Compared with SQT, KE displayed better test-retest reliability and agreement for MEPMAX whereas V50, force, and EMG were similarly reliable. Force (p = 0.01) and MEPMAX (p = 0.02) were also greater during KE despite a similar V50 (p = 0.11). Differences in test-retest reliability, absolute agreement, and between-group comparisons highlight the need to carefully select lower limb TMS assessment tasks and encourage future efforts to balance ecological validity with statistical sensitivity.
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Affiliation(s)
- F Proessl
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition University of Pittsburgh, Pittsburgh, PA, USA
| | - M E Beckner
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition University of Pittsburgh, Pittsburgh, PA, USA
| | - A M Sinnott
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition University of Pittsburgh, Pittsburgh, PA, USA
| | - S R Eagle
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition University of Pittsburgh, Pittsburgh, PA, USA
| | - A D LaGoy
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition University of Pittsburgh, Pittsburgh, PA, USA; Department of Psychiatry, University of Pittsburgh Medical School, Pittsburgh, PA, USA
| | - W R Conkright
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition University of Pittsburgh, Pittsburgh, PA, USA
| | - M C Canino
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition University of Pittsburgh, Pittsburgh, PA, USA
| | - A J Sterczala
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition University of Pittsburgh, Pittsburgh, PA, USA
| | - P P Midhe Ramkumar
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition University of Pittsburgh, Pittsburgh, PA, USA
| | - B M Sciavolino
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition University of Pittsburgh, Pittsburgh, PA, USA
| | - C Connaboy
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition University of Pittsburgh, Pittsburgh, PA, USA
| | - F Ferrarelli
- Department of Psychiatry, University of Pittsburgh Medical School, Pittsburgh, PA, USA
| | - A Germain
- Department of Psychiatry, University of Pittsburgh Medical School, Pittsburgh, PA, USA
| | - B C Nindl
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition University of Pittsburgh, Pittsburgh, PA, USA
| | - S D Flanagan
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition University of Pittsburgh, Pittsburgh, PA, USA.
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Flanagan SD, Proessl F, Dunn-Lewis C, Sterczala AJ, Connaboy C, Canino MC, Beethe AZ, Eagle SR, Szivak TK, Onate JA, Volek JS, Maresh CM, Kaeding CC, Kraemer WJ. Differences in brain structure and theta burst stimulation-induced plasticity implicate the corticomotor system in loss of function after musculoskeletal injury. J Neurophysiol 2021; 125:1006-1021. [PMID: 33596734 DOI: 10.1152/jn.00689.2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Traumatic musculoskeletal injury (MSI) may involve changes in corticomotor structure and function, but direct evidence is needed. To determine the corticomotor basis of MSI, we examined interactions among skeletomotor function, corticospinal excitability, corticomotor structure (cortical thickness and white matter microstructure), and intermittent theta burst stimulation (iTBS)-induced plasticity. Nine women with unilateral anterior cruciate ligament rupture (ACL) 3.2 ± 1.1 yr prior to the study and 11 matched controls (CON) completed an MRI session followed by an offline plasticity-probing protocol using a randomized, sham-controlled, double-blind, cross-over study design. iTBS was applied to the injured (ACL) or nondominant (CON) motor cortex leg representation (M1LEG) with plasticity assessed based on changes in skeletomotor function and corticospinal excitability compared with sham iTBS. The results showed persistent loss of function in the injured quadriceps, compensatory adaptations in the uninjured quadriceps and both hamstrings, and injury-specific increases in corticospinal excitability. Injury was associated with lateralized reductions in paracentral lobule thickness, greater centrality of nonleg corticomotor regions, and increased primary somatosensory cortex leg area inefficiency and eccentricity. Individual responses to iTBS were consistent with the principles of homeostatic metaplasticity; corresponded to injury-related differences in skeletomotor function, corticospinal excitability, and corticomotor structure; and suggested that corticomotor adaptations involve both hemispheres. Moreover, iTBS normalized skeletomotor function and corticospinal excitability in ACL. The results of this investigation directly confirm corticomotor involvement in chronic loss of function after traumatic MSI, emphasize the sensitivity of the corticomotor system to skeletomotor events and behaviors, and raise the possibility that brain-targeted therapies could improve recovery.NEW & NOTEWORTHY Traumatic musculoskeletal injuries may involve adaptive changes in the brain that contribute to loss of function. Our combination of neuroimaging and theta burst transcranial magnetic stimulation (iTBS) revealed distinct patterns of iTBS-induced plasticity that normalized differences in muscle and brain function evident years after unilateral knee ligament rupture. Individual responses to iTBS corresponded to injury-specific differences in brain structure and physiological activity, depended on skeletomotor deficit severity, and suggested that corticomotor adaptations involve both hemispheres.
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Affiliation(s)
- Shawn D Flanagan
- Department of Human Sciences, The Ohio State University, Columbus, Ohio.,Neuromuscular Research Laboratory, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Felix Proessl
- Neuromuscular Research Laboratory, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Courtenay Dunn-Lewis
- Department of Cardiothoracic Surgery, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Adam J Sterczala
- Neuromuscular Research Laboratory, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Chris Connaboy
- Neuromuscular Research Laboratory, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Maria C Canino
- Neuromuscular Research Laboratory, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Anne Z Beethe
- Neuromuscular Research Laboratory, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Shawn R Eagle
- Neuromuscular Research Laboratory, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Tunde K Szivak
- Department of Health Sciences, Merrimack College, North Andover, Massachusetts
| | - James A Onate
- School of Health and Rehabilitation Sciences, College of Medicine, The Ohio State University, Columbus, Ohio
| | - Jeff S Volek
- Department of Human Sciences, The Ohio State University, Columbus, Ohio
| | - Carl M Maresh
- Department of Human Sciences, The Ohio State University, Columbus, Ohio
| | - Christopher C Kaeding
- Sports Health and Performance Institute, Department of Orthopaedics, The Ohio State University, Columbus, Ohio
| | - William J Kraemer
- Department of Human Sciences, The Ohio State University, Columbus, Ohio
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Proessl F, Canino MC, Beckner ME, Sinnott AM, Eagle SR, LaGoy AD, Conkright WR, Sterczala AJ, Connaboy C, Ferrarelli F, Germain A, Nindl BC, Flanagan SD. Characterizing off-target corticospinal responses to double-cone transcranial magnetic stimulation. Exp Brain Res 2021; 239:1099-1110. [PMID: 33547521 DOI: 10.1007/s00221-021-06044-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 01/18/2021] [Indexed: 10/22/2022]
Abstract
INTRODUCTION The double-cone coil (D-CONE) is frequently used in transcranial magnetic stimulation (TMS) experiments that target the motor cortex (M1) lower-limb representation. Anecdotal evidence and modeling studies have shed light on the off-target effects of D-CONE TMS but the physiological extent remains undetermined. PURPOSE To characterize the off-target effects of D-CONE TMS based on bilateral corticospinal responses in the legs and hands. METHODS Thirty (N = 30) participants (9 women, age: 26 ± 5yrs) completed a stimulus-response curve procedure with D-CONE TMS applied to the dominant vastus lateralis (cVL) and motor-evoked potentials (MEPs) recorded in each active VL and resting first dorsal interosseous (FDI). As a positive control (CON), the dominant FDI was directly targeted with a figure-of-eight coil and MEPs were similarly recorded in each active FDI and resting VL. MEPMAX, V50 and MEP latencies were compared with repeated-measures ANOVAs or mixed-effects analysis and Bonferroni-corrected pairwise comparisons. RESULTS Off-target responses were evident in all muscles, with similar MEPMAX in the target (cVL) and off-target (iVL) leg (p = 0.99) and cFDI compared with CON (p = 0.99). cFDI and CON MEPMAX were greater than iFDI (p < 0.01). A main effect of target (p < 0.001) indicated that latencies were shorter with CON but similar in all muscles with D-CONE. DISCUSSION Concurrent MEP recordings in bilateral upper- and lower-extremity muscles confirm that lower-limb D-CONE TMS produces substantial distance-dependent off-target effects. In addition to monitoring corticospinal responses in off-target muscles to improve targeting accuracy in real-time, future studies may incorporate off-target information into statistical models post-hoc.
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Affiliation(s)
- F Proessl
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, 3860 South Water St, Pittsburgh, PA, 15203, USA
| | - M C Canino
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, 3860 South Water St, Pittsburgh, PA, 15203, USA
| | - M E Beckner
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, 3860 South Water St, Pittsburgh, PA, 15203, USA
| | - A M Sinnott
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, 3860 South Water St, Pittsburgh, PA, 15203, USA
| | - S R Eagle
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, 3860 South Water St, Pittsburgh, PA, 15203, USA
| | - A D LaGoy
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, 3860 South Water St, Pittsburgh, PA, 15203, USA.,Department of Psychiatry, University of Pittsburgh Medical School, 3811 O'Hara Street, Pittsburgh, PA, 15213, USA
| | - W R Conkright
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, 3860 South Water St, Pittsburgh, PA, 15203, USA
| | - A J Sterczala
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, 3860 South Water St, Pittsburgh, PA, 15203, USA
| | - C Connaboy
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, 3860 South Water St, Pittsburgh, PA, 15203, USA
| | - F Ferrarelli
- Department of Psychiatry, University of Pittsburgh Medical School, 3811 O'Hara Street, Pittsburgh, PA, 15213, USA
| | - A Germain
- Department of Psychiatry, University of Pittsburgh Medical School, 3811 O'Hara Street, Pittsburgh, PA, 15213, USA
| | - B C Nindl
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, 3860 South Water St, Pittsburgh, PA, 15203, USA
| | - S D Flanagan
- Neuromuscular Research Laboratory/Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences, University of Pittsburgh, 3860 South Water St, Pittsburgh, PA, 15203, USA.
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Eagle SR, Kontos AP, Collins MW, Connaboy C, Flanagan SD. Network Analysis of Sport-Related Concussion Research During the Past Decade (2010-2019). J Athl Train 2021; 56:454353. [PMID: 33543307 PMCID: PMC8063657 DOI: 10.4085/1062-6050-0280.20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
CONTEXT Research into sport-related concussion (SRC) has grown substantially over the past decade, yet no authors to date have synthesized developments over this critical time period. OBJECTIVE To apply a network-analysis approach in evaluating trends in the SRC literature using a comprehensive search of original, peer-reviewed research articles involving human participants published between January 1, 2010, and December 15, 2019. DESIGN Narrative review. MAIN OUTCOME MEASURE(S) Bibliometric maps were derived from a comprehensive search of all published, peer-reviewed SRC articles in the Web of Science database. A clustering algorithm was used to evaluate associations among journals, organizations or institutions, authors, and key words. The online search yielded 6130 articles, 528 journals, 7598 authors, 1966 organizations, and 3293 key words. RESULTS The analysis supported 5 thematic clusters of journals: (1) biomechanics/sports medicine (n = 15), (2) pediatrics/rehabilitation (n = 15), (3) neurotrauma/neurology/neurosurgery (n = 11), (4) general sports medicine (n = 11), and (5) neuropsychology (n = 7). The analysis identified 4 organizational clusters of hub institutions: (1) University of North Carolina (n = 19), (2) University of Toronto (n = 19), (3) University of Michigan (n = 11), and (4) University of Pittsburgh (n = 10). Network analysis revealed 8 clusters for SRC key words, each with a central topic area: (1) epidemiology (n = 14), (2) rehabilitation (n = 12), (3) biomechanics (n = 11), (4) imaging (n = 10), (5) assessment (n = 9), (6) mental health/chronic traumatic encephalopathy (n = 9), (7) neurocognition (n = 8), and (8) symptoms/impairments (n = 5). CONCLUSIONS The findings suggest that during the past decade SRC research has (1) been published primarily in sports medicine, pediatric, and neuro-focused journals, (2) involved a select group of researchers from several key institutions, and (3) concentrated on new topical areas, including treatment or rehabilitation and mental health.
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Affiliation(s)
- Shawn R. Eagle
- Department of Orthopaedic Surgery, University of Pittsburgh, PA
| | | | | | - Chris Connaboy
- Neuromuscular Research Laboratory, University of Pittsburgh, PA
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Proessl F, Dretsch MN, Connaboy C, Lovalekar M, Dunn-Lewis C, Canino MC, Sterczala AJ, Deshpande G, Katz JS, Denney TS, Flanagan SD. Structural Connectome Disruptions in Military Personnel with Mild Traumatic Brain Injury and Post-Traumatic Stress Disorder. J Neurotrauma 2020; 37:2102-2112. [DOI: 10.1089/neu.2020.6999] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Affiliation(s)
- Felix Proessl
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Michael N. Dretsch
- U.S. Army Medical Research Directorate-West, Walter Reed Army Institute of Research, Joint Base Lewis-McChord, Washington, USA
- U.S. Army Aeromedical Research Laboratory, Fort Rucker, Alabama, USA
- Department of Psychological Sciences, Auburn University, Auburn, Alabama, USA
| | - Chris Connaboy
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Mita Lovalekar
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Courtenay Dunn-Lewis
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Maria C. Canino
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Adam J. Sterczala
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Gopikrishna Deshpande
- Department of Psychological Sciences, Auburn University, Auburn, Alabama, USA
- Department of Electrical and Computer Engineering, Auburn University, Auburn, Alabama, USA
- Alabama Advanced Imaging Consortium, Alabama, USA
- Center for Neuroscience, Auburn University, Auburn, Alabama, USA
- School of Psychology, Capital Normal University, Beijing, China
| | - Jeffrey S. Katz
- Department of Psychological Sciences, Auburn University, Auburn, Alabama, USA
- Department of Electrical and Computer Engineering, Auburn University, Auburn, Alabama, USA
- Alabama Advanced Imaging Consortium, Alabama, USA
- Center for Neuroscience, Auburn University, Auburn, Alabama, USA
| | - Thomas S. Denney
- Department of Psychological Sciences, Auburn University, Auburn, Alabama, USA
- Department of Electrical and Computer Engineering, Auburn University, Auburn, Alabama, USA
- Alabama Advanced Imaging Consortium, Alabama, USA
- Center for Neuroscience, Auburn University, Auburn, Alabama, USA
| | - Shawn D. Flanagan
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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Krajewski KT, Bansbach HM, McLean L, McKenzie C, Rawcliffe A, Graham SM, Flanagan SD, Pourmoghaddam A, Dettmer M, Connaboy C. Effects of Short-Term Unilateral Strength Training on Measures of Postural Control When Wearing "Operationally Relevant" Backpack Loads. J Strength Cond Res 2020; 34:2743-2750. [PMID: 32956262 DOI: 10.1519/jsc.0000000000003794] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Krajewski, KT, Bansbach, HM, McLean, L, McKenzie, C, Rawcliffe, A, Graham, SM, Flanagan, SD, Pourmoghaddam, A, Dettmer, M, and Connaboy, C. Effects of short-term unilateral strength training on measures of postural control when wearing "operationally relevant" backpack loads. J Strength Cond Res 34(10): 2743-2750, 2020-To examine the effects of "operationally relevant" loads on postural stability and to determine the effects of unilateral and bilateral strength training programs on postural stability in healthy, recruit-aged men. Fifteen subjects were randomly assigned to either a unilateral (UL; n = 7) or bilateral (BL; n = 8) strength training group, which performed strength training 3 times a week for 4 weeks. Subjects completed the following pretest and post-test assessments: 1 repetition maximum in bilateral (1RM-BL) and unilateral (1RM-UL) stance positions and bilateral and unilateral balance tasks with eyes open and eyes closed. Balance tasks were performed over 3 loading conditions: body mass (BM), 50% BM, and 70% BM. Sample entropy (SE) and root mean square (RMS) were calculated from the center of pressures collected during each balance assessment. The UL strength training group showed significant improvement after training in both 1RM-UL (p < 0.01) and 1RM-BL (p < 0.01). The BL strength training group only showed significant improvement in 1RM-BL (p = 0.01). There was a significant main effect of load on RMS (p < 0.05) across all balance tasks with RMS increasing with increasing load. Sample entropy was found to decrease with increasing load in the unilateral eyes open and bilateral stance tasks. Significant increases in strength (∼10 to -29%) were observed; however, increased strength alone is not enough to mitigate the effects of load carriage on the postural control, even when training is performed in stance positions that are posturally challenging. Therefore, "operationally relevant" loads negatively impact postural stability in novice load carriers when assessing nonlinear measures.
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Affiliation(s)
- Kellen T Krajewski
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Heather M Bansbach
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania.,University of Virginia, School of Engineering and Applied Science, Virginia
| | - Lucy McLean
- Edinburgh Napier University, Edinburgh, Scotland, United Kingdom
| | - Clive McKenzie
- Edinburgh Napier University, Edinburgh, Scotland, United Kingdom
| | - Alex Rawcliffe
- Department of Occupational Medicine, HQ ARITC, UK Ministry of Defence, United Kingdom; and
| | - Scott M Graham
- Edinburgh Napier University, Edinburgh, Scotland, United Kingdom
| | - Shawn D Flanagan
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania
| | | | - Marius Dettmer
- Memorial Bone & Joint Research Foundation, Houston, Texas
| | - Chris Connaboy
- Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, Pennsylvania
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