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Sigrist S, Abel MG, Best SA, Bollinger LM. Sleep restriction reduces voluntary isometric quadriceps strength through reduced neuromuscular efficiency, not impaired contractile performance. Eur J Appl Physiol 2024:10.1007/s00421-024-05535-x. [PMID: 38935151 DOI: 10.1007/s00421-024-05535-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2024] [Accepted: 06/10/2024] [Indexed: 06/28/2024]
Abstract
Acute sleep restriction (SR) reduces strength through an unknown mechanism. PURPOSE To determine how SR affects quadriceps contractile function and recruitment. METHODS Eighteen healthy subjects (9 M, 9F, age 23.8 ± 2.8y) underwent isometric (maximal and submaximal), isokinetic (300-60°·s-1), and interpolated twitch (ITT) assessment of knee extensors following 3d of adequate sleep (SA; 7-9 h·night-1), 3d of SR (5 h·night-1), and 7d of washout (WO; 7-9 h·night-1). RESULTS Compared to SA (227.9 ± 76.6Nm) and WO (228.19 ± 62.9Nm), MVIC was lesser following SR (209.9 ± 73.9Nm; p = 0.006) and this effect was greater for males (- 9.8 v. - 4.8%). There was no significant effect of sleep or sleep x speed interaction on peak isokinetic torque. Peak twitch torque was greater in the potentiated state, but no significant effect of sleep was noted. Males displayed greater potentiation of peak twitch torque (12 v. 7.5%) and rate of torque development (16.7 v. 8.2%) than females but this was not affected by sleep condition. ITT-assessed voluntary activation did not vary among sleep conditions (SA: 81.8 ± 13.1% v. SR: 84.4 ± 12.6% v. WO 84.9 ± 12.6%; p = 0.093). SR induced a leftward shift in Torque-EMG relationship at high torque output in both sexes. Compared to SA, females displayed greater y-intercept and lesser slope with SR and WO and males displayed lesser y-intercept and greater slope with SR and WO. CONCLUSIONS Three nights of SR decreases voluntary isometric knee extensor strength, but not twitch contractile properties. Sex-specific differences in neuromuscular efficiency may explain the greater MVIC reduction in males following SR.
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Affiliation(s)
- S Sigrist
- Department of Kinesiology and Health Promotion, University of Kentucky, Lexington, KY, 40506, USA
| | - M G Abel
- Department of Kinesiology and Health Promotion, University of Kentucky, Lexington, KY, 40506, USA
| | - S A Best
- Department of Kinesiology and Health Promotion, University of Kentucky, Lexington, KY, 40506, USA
| | - L M Bollinger
- Department of Kinesiology and Health Promotion, University of Kentucky, Lexington, KY, 40506, USA.
- Center for Muscle Biology, University of Kentucky, Lexington, KY, USA.
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Guo Y, Jones EJ, Smart TF, Altheyab A, Gamage N, Stashuk DW, Piasecki J, Phillips BE, Atherton PJ, Piasecki M. Sex disparities of human neuromuscular decline in older humans. J Physiol 2024. [PMID: 38857412 DOI: 10.1113/jp285653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 05/07/2024] [Indexed: 06/12/2024] Open
Abstract
Females typically live longer than males but, paradoxically, spend a greater number of later years in poorer health. The neuromuscular system is a critical component of the progression to frailty, and motor unit (MU) characteristics differ by sex in healthy young individuals and may adapt to ageing in a sex-specific manner due to divergent hormonal profiles. The purpose of this study was to investigate sex differences in vastus lateralis (VL) MU structure and function in early to late elderly humans. Intramuscular electromyography signals from 50 healthy older adults (M/F: 26/24) were collected from VL during standardized submaximal contractions and decomposed to quantify MU characteristics. Muscle size and neuromuscular performance were also measured. Females had higher MU firing rate (FR) than males (P = 0.025), with no difference in MU structure or neuromuscular junction transmission (NMJ) instability. All MU characteristics increased from low- to mid-level contractions (P < 0.05) without sex × level interactions. Females had smaller cross-sectional area of VL, lower strength and poorer force steadiness (P < 0.05). From early to late elderly, both sexes showed decreased neuromuscular function (P < 0.05) without sex-specific patterns. Higher VL MUFRs at normalized contraction levels previously observed in young are also apparent in old individuals, with no sex-based difference of estimates of MU structure or NMJ transmission instability. From early to late elderly, the deterioration of neuromuscular function and MU characteristics did not differ between sexes, yet function was consistently greater in males. These parallel trajectories underscore the lower initial level for older females and may offer insights into identifying critical intervention periods. KEY POINTS: Females generally exhibit an extended lifespan when compared to males, yet this is accompanied by a poorer healthspan and higher rates of frailty. In healthy young people, motor unit firing rate (MUFR) at normalized contraction intensities is widely reported to be higher in females than in age-matched males. Here we show in 50 people that older females have higher MUFR than older males with little difference in other MU parameters. The trajectory of decline from early to late elderly does not differ between sexes, yet function is consistently lower in females. These findings highlight distinguishable sex disparities in some MU characteristics and neuromuscular function, and suggest early interventions are needed for females to prevent functional deterioration to reduce the ageing health-sex paradox.
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Affiliation(s)
- Yuxiao Guo
- Institute of Sports Medicine and Health, Chengdu Sport University, Chengdu, China
- Centre of Metabolism, Ageing & Physiology (COMAP), MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, School of Medicine, University of Nottingham, Nottingham, UK
| | - Eleanor J Jones
- Centre of Metabolism, Ageing & Physiology (COMAP), MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, School of Medicine, University of Nottingham, Nottingham, UK
| | - Thomas F Smart
- Centre of Metabolism, Ageing & Physiology (COMAP), MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, School of Medicine, University of Nottingham, Nottingham, UK
| | - Abdulmajeed Altheyab
- Centre of Metabolism, Ageing & Physiology (COMAP), MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, School of Medicine, University of Nottingham, Nottingham, UK
- College of Applied Medical Sciences, King Saud bin Abdulaziz University for Health Science, Riyadh, Saudi Arabia
| | - Nishadi Gamage
- Centre of Metabolism, Ageing & Physiology (COMAP), MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, School of Medicine, University of Nottingham, Nottingham, UK
- Neurophysiology of Human Movement Group, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, Australia
| | - Daniel W Stashuk
- Department of Systems Design Engineering, University of Waterloo, Waterloo, Ontario, Canada
| | - Jessica Piasecki
- Musculoskeletal Physiology Research Group, Sport, Health and Performance Enhancement Research Centre, Nottingham Trent University, Nottingham, UK
| | - Bethan E Phillips
- Centre of Metabolism, Ageing & Physiology (COMAP), MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, School of Medicine, University of Nottingham, Nottingham, UK
| | - Philip J Atherton
- Centre of Metabolism, Ageing & Physiology (COMAP), MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, School of Medicine, University of Nottingham, Nottingham, UK
| | - Mathew Piasecki
- Centre of Metabolism, Ageing & Physiology (COMAP), MRC-Versus Arthritis Centre for Musculoskeletal Ageing Research, National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, School of Medicine, University of Nottingham, Nottingham, UK
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Cobian DG, Oppenheim ZR, Roehl TJ, Joachim MR, Heiderscheit BC. Knee Extensor Torque Steadiness and Quadriceps Activation Variability in Collegiate Athletes 4, 6, and 12 Months After ACL Reconstruction. Orthop J Sports Med 2024; 12:23259671241253843. [PMID: 38867919 PMCID: PMC11168251 DOI: 10.1177/23259671241253843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 11/16/2023] [Indexed: 06/14/2024] Open
Abstract
Background Quadriceps performance after anterior cruciate ligament reconstruction (ACLR) is typically characterized by peak force/torque, but the ability to generate consistent knee extensor torque may be clinically meaningful. Purpose/Hypothesis The purpose of this study was to evaluate knee extensor torque steadiness and quadriceps activation variability in collegiate athletes 4 to 12 months after ACLR. It was hypothesized that between-limb asymmetries in torque steadiness and activation variability would be observed and that steadiness would be associated with activation variability and peak knee extensor torque symmetry. Study Design Case-control study; Level of evidence, 3. Methods A total of 30 National Collegiate Athletic Association Division I athletes completed maximal voluntary isometric contractions 4, 6, and 12 months after ACLR. Torque and surface electromyography of the superficial quadriceps were recorded. Torque steadiness was calculated as the mean difference between initial and low-pass filtered torque signals and was expressed as a percentage of peak torque. Quadriceps activation variability was calculated similarly and was expressed as a percentage of peak electromyography. Linear mixed models were used to assess change in torque steadiness and activation variability over time. Associations between torque steadiness of the operated limb, activation variability, and quadriceps strength symmetry were evaluated using the Spearman correlation coefficient. Results Limb-by-time interactions were detected for torque steadiness and activation variability (P < .001), with reductions (improvements) in limb steadiness and activation variability observed with increasing time since surgery. Between-limb differences in torque steadiness and activation variability were observed at 4 and 6 months postoperatively (P < .05). Significant associations between operated limb torque steadiness and quadriceps activation variability were observed at 4 months (P < .001) and 6 months (P < .01). Torque steadiness of the operated limb was associated with peak knee extensor torque symmetry at 4 months (r S = -0.49; P < .01) and 6 months (r S = -0.49; P < .01). Conclusion In collegiate athletes, impaired knee extensor torque steadiness of the operated limb and associated abnormal quadriceps activation patterns were observed 4 to 12 months after ACLR, and the consistency of knee extensor torque production was associated with greater quadriceps strength asymmetries, particularly 4 to 6 months after surgery. Operated limb torque steadiness and activation variability improved from 4 to 12 months after ACLR. Clinical assessment of knee extensor torque steadiness after ACLR may improve prognosis and specificity of rehabilitation efforts.
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Affiliation(s)
- Daniel G. Cobian
- Orthopedics and Rehabilitation, University of Wisconsin–Madison, Madison, Wisconsin, USA
- Badger Athletic Performance Program, University of Wisconsin–Madison, Madison, Wisconsin, USA
- Doctor of Physical Therapy Program, University of Wisconsin–Madison, Madison, Wisconsin, USA
| | - Zachary R. Oppenheim
- Badger Athletic Performance Program, University of Wisconsin–Madison, Madison, Wisconsin, USA
- Department of Biomedical Engineering, University of Wisconsin–Madison, Madison, Wisconsin, USA
| | - Tyler J. Roehl
- Badger Athletic Performance Program, University of Wisconsin–Madison, Madison, Wisconsin, USA
- Doctor of Physical Therapy Program, University of Wisconsin–Madison, Madison, Wisconsin, USA
| | - Mikel R. Joachim
- Orthopedics and Rehabilitation, University of Wisconsin–Madison, Madison, Wisconsin, USA
- Badger Athletic Performance Program, University of Wisconsin–Madison, Madison, Wisconsin, USA
| | - Bryan C. Heiderscheit
- Orthopedics and Rehabilitation, University of Wisconsin–Madison, Madison, Wisconsin, USA
- Badger Athletic Performance Program, University of Wisconsin–Madison, Madison, Wisconsin, USA
- Department of Biomedical Engineering, University of Wisconsin–Madison, Madison, Wisconsin, USA
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Labanca L, Tedeschi R, Mosca M, Benedetti MG. Individuals With Chronic Ankle Instability Show Abnormalities in Maximal and Submaximal Isometric Strength of the Knee Extensor and Flexor Muscles. Am J Sports Med 2024; 52:1328-1335. [PMID: 38459686 PMCID: PMC10986150 DOI: 10.1177/03635465241232090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 12/15/2023] [Indexed: 03/10/2024]
Abstract
BACKGROUND It has been shown that chronic ankle instability (CAI) leads to abnormalities in neuromuscular control of more proximal joints than the ankle. Although strength of the hip and the ankle muscles has been largely investigated providing concordant results, limited evidence with contrasting results has been reported regarding knee extensor and flexor muscles. PURPOSE To investigate maximal and submaximal isometric muscle strength in individuals with CAI. STUDY DESIGN Controlled laboratory study. METHODS Fifteen participants with unilateral CAI and 15 healthy matched controls were recruited. To quantify maximal strength, peak forces were recorded during a maximal isometric voluntary contraction of knee extensor and flexor muscles at 30° and 90° of knee flexion and normalized by the body weight of each participant. At both angles, submaximal isometric contractions at 20%, 50%, and 80% of the maximal voluntary isometric contraction were performed to analyze strength steadiness, in terms of coefficient of variation, and strength accuracy, in terms of absolute error. During all the assessments, knee extensor and flexor muscle activation was recorded by means of surface electromyography. RESULTS Knee flexor maximal isometric strength was significantly lower in the injured limb of individuals with CAI in comparison with healthy controls at both 30° (0.15 ± 0.05 vs 0.20 ± 0.05; P < .05) and 90° (0.14 ± 0.04 vs 0.18 ± 0.05; P < .05). Knee extensor and flexor steadiness was significantly lower (higher coefficient of variation) in both the injured and the noninjured limbs of individuals with CAI in comparison with healthy individuals at 90° and at 30° for knee flexor steadiness of the injured limb. Knee extensor and flexor accuracy was lower (higher absolute error) in both the injured and noninjured limbs of individuals with CAI in comparison with healthy individuals, mainly at 30°, while at 90° it was lower only in the injured limb. No differences between the 2 groups were found for maximal isometric strength of knee extensor muscles, as well as for muscle activations. CONCLUSION Individuals with CAI show abnormalities in maximal and submaximal isometric strength of knee flexor muscles, and submaximal strength of the knee extensor muscles. Further studies should deeply investigate mechanisms leading to these abnormalities. CLINICAL RELEVANCE Rehabilitation interventions should consider abnormalities of neuromuscular control affecting joints more proximal than the ankle in individuals with CAI. REGISTRATION NCT05273177 (ClinicalTrials.gov identifier).
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Affiliation(s)
- Luciana Labanca
- Physical Medicine and Rehabilitation Unit, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy
| | - Roberto Tedeschi
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Massimiliano Mosca
- II Clinic of Orthopaedics and Traumatology, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy
| | - Maria Grazia Benedetti
- Physical Medicine and Rehabilitation Unit, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
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Uwamahoro R, Sundaraj K, Feroz FS. Effect of Forearm Postures and Elbow Joint Angles on Elbow Flexion Torque and Mechanomyography in Neuromuscular Electrical Stimulation of the Biceps Brachii. SENSORS (BASEL, SWITZERLAND) 2023; 23:8165. [PMID: 37836995 PMCID: PMC10575078 DOI: 10.3390/s23198165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 08/31/2023] [Accepted: 09/05/2023] [Indexed: 10/15/2023]
Abstract
Neuromuscular electrical stimulation plays a pivotal role in rehabilitating muscle function among individuals with neurological impairment. However, there remains uncertainty regarding whether the muscle's response to electrical excitation is affected by forearm posture, joint angle, or a combination of both factors. This study aimed to investigate the effects of forearm postures and elbow joint angles on the muscle torque and MMG signals. Measurements of the torque around the elbow and MMG of the biceps brachii (BB) muscle were conducted in 36 healthy subjects (age, 22.24 ± 2.94 years; height, 172 ± 0.5 cm; and weight, 67.01 ± 7.22 kg) using an in-house elbow flexion testbed and neuromuscular electrical stimulation (NMES) of the BB muscle. The BB muscle was stimulated while the forearm was positioned in the neutral, pronation, or supination positions. The elbow was flexed at angles of 10°, 30°, 60°, and 90°. The study analyzed the impact of the forearm posture(s) and elbow joint angle(s) on the root-mean-square value of the torque (TQRMS). Subsequently, various MMG parameters, such as the root-mean-square value (MMGRMS), the mean power frequency (MMGMPF), and the median frequency (MMGMDF), were analyzed along the longitudinal, lateral, and transverse axes of the BB muscle fibers. The test-retest interclass correlation coefficient (ICC21) for the torque and MMG ranged from 0.522 to 0.828. Repeated-measure ANOVAs showed that the forearm posture and elbow flexion angle significantly influenced the TQRMS (p < 0.05). Similarly, the MMGRMS, MMGMPF, and MMGMDF showed significant differences among all the postures and angles (p < 0.05). However, the combined main effect of the forearm posture and elbow joint angle was insignificant along the longitudinal axis (p > 0.05). The study also found that the MMGRMS and TQRMS increased with increases in the joint angle from 10° to 60° and decreased at greater angles. However, during this investigation, the MMGMPF and MMGMDF exhibited a consistent decrease in response to increases in the joint angle for the lateral and transverse axes of the BB muscle. These findings suggest that the muscle contraction evoked by NMES may be influenced by the interplay between actin and myosin filaments, which are responsible for muscle contraction and are, in turn, influenced by the muscle length. Because restoring the function of limbs is a common goal in rehabilitation services, the use of MMG in the development of methods that may enable the real-time tracking of exact muscle dimensional changes and activation levels is imperative.
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Affiliation(s)
- Raphael Uwamahoro
- Fakulti Kejuruteraan Elektronik dan Kejuruteraan Komputer, Universiti Teknikal Malaysia Melaka, Durian Tunggal 76100, Melaka, Malaysia; (R.U.); (F.S.F.)
- Regional Centre of Excellence in Biomedical Engineering and e-Health, University of Rwanda, Kigali P.O. Box 4285, Rwanda
| | - Kenneth Sundaraj
- Fakulti Kejuruteraan Elektronik dan Kejuruteraan Komputer, Universiti Teknikal Malaysia Melaka, Durian Tunggal 76100, Melaka, Malaysia; (R.U.); (F.S.F.)
| | - Farah Shahnaz Feroz
- Fakulti Kejuruteraan Elektronik dan Kejuruteraan Komputer, Universiti Teknikal Malaysia Melaka, Durian Tunggal 76100, Melaka, Malaysia; (R.U.); (F.S.F.)
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Linderman SE, Scarborough DM, Aspenleiter R, Stein HS, Berkson EM. Assessing Quadriceps Muscle Contraction Using a Novel Surface Mechanomyography Sensor during Two Neuromuscular Control Screening Tasks. SENSORS (BASEL, SWITZERLAND) 2023; 23:6031. [PMID: 37447881 DOI: 10.3390/s23136031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 06/22/2023] [Accepted: 06/22/2023] [Indexed: 07/15/2023]
Abstract
Electromyography (EMG) is the clinical standard for capturing muscle activation data to gain insight into neuromuscular control, yet challenges surrounding data analysis limit its use during dynamic tasks. Surface mechanomyography (sMMG) sensors are novel wearable devices that measure the physical output of muscle excursion during contraction, which may offer potential easy application to assess neuromuscular control. This study aimed to investigate sMMG detection of the timing patterns of muscle contraction compared to EMG. Fifteen healthy participants (mean age = 31.7 ± 9.1 y; eight males and seven females) were donned with EMG and sMMG sensors on their right quadriceps for simultaneous data capture during bilateral deep squats, and a subset performed three sets of repeated unilateral partial squats. No significant difference in the total duration of contraction was detected by EMG and sMMG during bilateral (p = 0.822) and partial (p = 0.246) squats. sMMG and EMG timing did not differ significantly for eccentric (p = 0.414) and concentric (p = 0.462) phases of muscle contraction during bilateral squats. The sMMG magnitude of quadriceps excursion demonstrated excellent intra-session retest reliability for bilateral (ICC3,1 = 0.962 mm) and partial (ICC3,1 = 0.936 mm, n = 10) squats. The sMMG sensors accurately and consistently provided key quadriceps muscle performance metrics during two physical activities commonly used to assess neuromuscular control for injury prevention, rehabilitation, and exercise training.
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Affiliation(s)
- Shannon E Linderman
- Department of Orthopaedic Surgery, Massachusetts General Hospital, Boston, MA 02114, USA
| | | | | | - Hannah S Stein
- Department of Orthopaedic Surgery, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Eric M Berkson
- Department of Orthopaedic Surgery, Massachusetts General Hospital, Boston, MA 02114, USA
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Zeng W, Hume DR, Lu Y, Fitzpatrick CK, Babcock C, Myers CA, Rullkoetter PJ, Shelburne KB. Modeling of active skeletal muscles: a 3D continuum approach incorporating multiple muscle interactions. Front Bioeng Biotechnol 2023; 11:1153692. [PMID: 37274172 PMCID: PMC10234509 DOI: 10.3389/fbioe.2023.1153692] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Accepted: 05/10/2023] [Indexed: 06/06/2023] Open
Abstract
Skeletal muscles have a highly organized hierarchical structure, whose main function is to generate forces for movement and stability. To understand the complex heterogeneous behaviors of muscles, computational modeling has advanced as a non-invasive approach to evaluate relevant mechanical quantities. Aiming to improve musculoskeletal predictions, this paper presents a framework for modeling 3D deformable muscles that includes continuum constitutive representation, parametric determination, model validation, fiber distribution estimation, and integration of multiple muscles into a system level for joint motion simulation. The passive and active muscle properties were modeled based on the strain energy approach with Hill-type hyperelastic constitutive laws. A parametric study was conducted to validate the model using experimental datasets of passive and active rabbit leg muscles. The active muscle model with calibrated material parameters was then implemented to simulate knee bending during a squat with multiple quadriceps muscles. A computational fluid dynamics (CFD) fiber simulation approach was utilized to estimate the fiber arrangements for each muscle, and a cohesive contact approach was applied to simulate the interactions among muscles. The single muscle simulation results showed that both passive and active muscle elongation responses matched the range of the testing data. The dynamic simulation of knee flexion and extension showed the predictive capability of the model for estimating the active quadriceps responses, which indicates that the presented modeling pipeline is effective and stable for simulating multiple muscle configurations. This work provided an effective framework of a 3D continuum muscle model for complex muscle behavior simulation, which will facilitate additional computational and experimental studies of skeletal muscle mechanics. This study will offer valuable insight into the future development of multiscale neuromuscular models and applications of these models to a wide variety of relevant areas such as biomechanics and clinical research.
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Affiliation(s)
- Wei Zeng
- Center for Orthopaedic Biomechanics, University of Denver, Denver, CO, United States
- Department of Mechanical Engineering, New York Institute of Technology, New York, NY, United States
| | - Donald R. Hume
- Center for Orthopaedic Biomechanics, University of Denver, Denver, CO, United States
| | - Yongtao Lu
- Department of Engineering Mechanics, Dalian University of Technology, Dalian, China
| | - Clare K. Fitzpatrick
- Mechanical and Biomedical Engineering, Boise State University, Boise, ID, United States
| | - Colton Babcock
- Mechanical and Biomedical Engineering, Boise State University, Boise, ID, United States
| | - Casey A. Myers
- Center for Orthopaedic Biomechanics, University of Denver, Denver, CO, United States
| | - Paul J. Rullkoetter
- Center for Orthopaedic Biomechanics, University of Denver, Denver, CO, United States
| | - Kevin B. Shelburne
- Center for Orthopaedic Biomechanics, University of Denver, Denver, CO, United States
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Blood Flow Restriction Therapy for 2 Weeks Prior to Anterior Cruciate Ligament Reconstruction Did Not Impact Quadriceps Strength Compared to Standard Therapy. Arthroscopy 2023; 39:373-381. [PMID: 35842062 DOI: 10.1016/j.arthro.2022.06.027] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 06/14/2022] [Accepted: 06/23/2022] [Indexed: 02/02/2023]
Abstract
PURPOSE To evaluate the efficacy of a 2-week home-based blood flow restriction (BFR) prehabiliation program on quadriceps strength and patient-reported outcomes prior to anterior cruciate ligament (ACL) reconstruction. METHODS Patients presenting with an ACL tear were randomized into two groups, BFR and control, at their initial clinic visit. Quadriceps strength was measured using a handheld dynamometer in order to calculate peak force, average force, and time to peak force during seated leg extension at the initial clinic visit and repeated on the day of surgery. All patients were provided education on standardized exercises to be performed 5 days per week for 2 weeks between the initial clinic visit and date of surgery. The BFR group was instructed to perform these exercises with a pneumatic cuff set to 80% of limb occlusion pressure placed over the proximal thigh. Patient-Reported Outcome Measurement System Physical Function (PROMIS-PF), knee range of motion, and quadriceps circumference were gathered at the initial clinic visit and day of surgery, and patients were monitored for adverse effects. RESULTS A total 45 patients met inclusion criteria and elected to participate. There were 23 patients randomized to the BFR group and 22 patients randomized into the control group. No significant differences were noted between the BFR and control groups in any demographic characteristics (48% vs 64% male [P = .271] and average age 26.5 ± 12.0 vs 27.0 ± 11.0 [P = .879] in BFR and control, respectively). During the initial clinic visit, there were no significant differences in quadriceps circumference, peak quadriceps force generation, time to peak force, average force, pain, and PROMIS scales (P > .05 for all). Following completion of a 2-week home prehabilitation protocol, all patients indeterminant of cohort demonstrated decreased strength loss in the operative leg compared to the nonoperative leg (P < .05 for both) However, there were no significant differences in any strength or outcome measures between the BFR and control groups (P > .05 for all). There were no complications experienced in either group, and both were compliant with the home-based prehabilitation program. CONCLUSIONS A 2-week standardized prehabilitation protocol preceding ACL reconstruction resulted in a significant improvement in personal quadriceps peak force measurements, both with and without the use of BFR. No difference in quadriceps circumference, strength, or patient reported outcomes were found between the BFR and the control group. The home-based BFR prehabiliation protocol was found to be feasible, accessible, and well tolerated by patients. LEVEL OF EVIDENCE Level II, randomized controlled trial with small effect size.
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Quadriceps motor evoked torque is a reliable measure of corticospinal excitability in individuals with anterior cruciate ligament reconstruction. J Electromyogr Kinesiol 2022; 67:102700. [PMID: 36063566 DOI: 10.1016/j.jelekin.2022.102700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 08/01/2022] [Accepted: 08/26/2022] [Indexed: 12/14/2022] Open
Abstract
This study comprehensively evaluated the test-retest reliability of raw and normalized quadriceps motor evoked responses elicited by transcranial magnetic stimulation (TMS) in individuals with anterior cruciate ligament (ACL) reconstruction. Fifteen participants were tested on three different days that were separated at least by 24 h. Motor evoked responses were collected during a small background contraction on the reconstructed leg across a range of TMS intensities using torque (MEPTORQUE) and electromyographic (MEPEMG) responses. MEPTORQUE and MEPEMG were evaluated using different normalization procedures (raw, normalized to maximum voluntary isometric contraction [MVIC], peak MEP, and background contraction). MEPTORQUE was also normalized to the magnetically-evoked peripheral resting twitch torque. The area under the recruitment curve was computed for both raw and normalized MEPs. Intraclass correlation coefficients (ICCs) were determined to assess test-retest reliability. Results indicated that MEPTORQUE generally showed greater reliability than MEPEMG for all normalization procedures. Vastus medialis MEPEMG generally showed greater reliability than rectus femoris MEPEMG. Finally, both MEPTORQUE and MEPEMG exhibited good reliability, even when not normalized. These findings indicate that MEPTORQUE and MEPEMG offer reliable measures of corticospinal function and suggest that MEPTORQUE is a suitable alternative to MEPEMG for measuring quadriceps corticospinal excitability in individuals with ACL reconstruction.
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Kukić F, Mrdaković V, Stanković A, Ilić D. Effects of Knee Extension Joint Angle on Quadriceps Femoris Muscle Activation and Exerted Torque in Maximal Voluntary Isometric Contraction. BIOLOGY 2022; 11:biology11101490. [PMID: 36290394 PMCID: PMC9598811 DOI: 10.3390/biology11101490] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 10/06/2022] [Accepted: 10/06/2022] [Indexed: 11/30/2022]
Abstract
This study investigated the effects of knee joint angle on muscle activation, exerted torque, and whether the knee angle affects the muscle activation−torque ratio. Nine healthy adult male participants participated in the study. They performed maximal voluntary isometric contraction (MVIC) at six (80°, 90°, 100°, 110°, 120°, and 130°) different knee joint angles (i.e., angles between the thigh and shin bones). Their maximal torque was assessed utilizing an isokinetic chair, while their muscle activation (root mean square [RMS]) was assessed using an eight-channel single differential surface EMG sensor. For the purposes of the torque−knee angle relationship and muscle activation−knee angle relationship, the torque and RMS were normalized relative to the maximal value obtained by each participant. To evaluate the muscle activation−torque ratio in function of knee angle, RMS was normalized relative to the corresponding torque obtained at each knee angle. Repeated measure analysis of variance was used to investigate the effects of knee angle on muscle activation, torque, and muscle activation−torque ratio. There was a significant effect of knee joint angle on normalized torque (F = 27.521, p < 0.001), while the activation of vastus lateralis and vastus medialis remained unchanged. The changes in knee angle affected the muscle activation−torque ratio of vastus lateralis (Chi-square = 16.246, p = 0.006) but not the vastus medialis. These results suggest that knee joint angles from 80° to 130° provide a stable milieu for muscle electrification, while mechanical factor such as knee joint angle (i.e., lever arm length) affect the torque output when one needs to contract quadriceps maximally during the isometric contraction.
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Affiliation(s)
- Filip Kukić
- Police Sports Education Center, Abu Dhabi Police, Abu Dhabi 253, United Arab Emirates
- Correspondence:
| | - Vladimir Mrdaković
- Faculty of Sport and Physical Education, University of Belgrade, 11030 Belgrade, Serbia
| | - Aleksandar Stanković
- Faculty of Sport and Physical Education, University of Belgrade, 11030 Belgrade, Serbia
| | - Duško Ilić
- Faculty of Sport and Physical Education, University of Belgrade, 11030 Belgrade, Serbia
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Kellis E, Blazevich AJ. Hamstrings force-length relationships and their implications for angle-specific joint torques: a narrative review. BMC Sports Sci Med Rehabil 2022; 14:166. [PMID: 36064431 PMCID: PMC9446565 DOI: 10.1186/s13102-022-00555-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 08/22/2022] [Indexed: 11/10/2022]
Abstract
Temporal biomechanical and physiological responses to physical activity vary between individual hamstrings components as well as between exercises, suggesting that hamstring muscles operate differently, and over different lengths, between tasks. Nevertheless, the force-length properties of these muscles have not been thoroughly investigated. The present review examines the factors influencing the hamstrings’ force-length properties and relates them to in vivo function. A search in four databases was performed for studies that examined relations between muscle length and force, torque, activation, or moment arm of hamstring muscles. Evidence was collated in relation to force-length relationships at a sarcomere/fiber level and then moment arm-length, activation-length, and torque-joint angle relations. Five forward simulation models were also used to predict force-length and torque-length relations of hamstring muscles. The results show that, due to architectural differences alone, semitendinosus (ST) produces less peak force and has a flatter active (contractile) fiber force-length relation than both biceps femoris long head (BFlh) and semimembranosus (SM), however BFlh and SM contribute greater forces through much of the hip and knee joint ranges of motion. The hamstrings’ maximum moment arms are greater at the hip than knee, so the muscles tend to act more as force producers at the hip but generate greater joint rotation and angular velocity at the knee for a given muscle shortening length and speed. However, SM moment arm is longer than SM and BFlh, partially alleviating its reduced force capacity but also reducing its otherwise substantial excursion potential. The current evidence, bound by the limitations of electromyography techniques, suggests that joint angle-dependent activation variations have minimal impact on force-length or torque-angle relations. During daily activities such as walking or sitting down, the hamstrings appear to operate on the ascending limbs of their force-length relations while knee flexion exercises performed with hip angles 45–90° promote more optimal force generation. Exercises requiring hip flexion at 45–120° and knee extension 45–0° (e.g. sprint running) may therefore evoke greater muscle forces and, speculatively, provide a more optimum adaptive stimulus. Finally, increases in resistance to stretch during hip flexion beyond 45° result mainly from SM and BFlh muscles.
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Affiliation(s)
- Eleftherios Kellis
- Laboratory of Neuromechanics, Department of Physical Education and Sport Sciences at Serres, Aristotle University of Thessaloniki, TEFAA Serres, 62100, Serres, Greece.
| | - Anthony J Blazevich
- Centre for Human Performance, School of Medical and Health Sciences, Edith Cowan University, Joondalup, 6027, Australia
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Murphy MT, Wang N, Felson DT, Nevitt MC, Lewis CE, Frey-Law L, Guermazi A, Segal NA. Association between hamstring coactivation during isokinetic quadriceps strength testing and knee cartilage worsening over 24 months. Osteoarthritis Cartilage 2022; 30:823-831. [PMID: 35307535 PMCID: PMC9450915 DOI: 10.1016/j.joca.2022.03.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 02/24/2022] [Accepted: 03/07/2022] [Indexed: 02/02/2023]
Abstract
OBJECTIVE This study aimed to determine longitudinal associations, including sex-specific differences, between greater knee flexor antagonist coactivation and worsening cartilage morphology in knees with or at risk for osteoarthritis (OA). DESIGN Baseline measurements were collected at the 60-month visit of a longitudinal osteoarthritis study following community-dwelling participants (MOST). Knee flexor and extensor muscle activity were measured with surface electromyography during a maximal isokinetic knee extension task. MRI analyzed knee cartilage morphology at baseline and 24-month follow-up. Multivariable adjusted logistic regression models were used to assess associations between coactivation level and cartilage morphology worsening. RESULTS Analysis of 373 women (mean ± SD age 67.4 ± 7.3 years and BMI 29.7 ± 5.0 kg/m2) and 240 men (66.5 ± 7.8 years and 29.9 ± 4.5 kg/m2) revealed that women had greater medial (P < 0.001), lateral (P < 0.001), and combined (P < 0.001) hamstring coactivation than men. In both sexes, combined hamstring coactivation was associated with patellofemoral cartilage morphology worsening [1.23 (1.02, 1.49)] and to a less significant degree with whole knee cartilage morphology worsening [1.21 (0.98, 1.49)]. In men, greater combined hamstring coactivation was associated with increased risk for whole knee [1.59 (1.06, 2.39)] and patellofemoral [1.38 (1.01, 1.88)] cartilage morphology worsening and point estimates suggested association between medial hamstring coactivation and medial tibiofemoral cartilage morphology worsening. No significant associations were detected between greater hamstring coactivation and cartilage morphology worsening in women. CONCLUSIONS These findings suggest a longitudinal relationship between antagonist hamstring coactivation during isokinetic knee extensor testing and worsening of cartilage morphology over 24 months in men with or at risk for knee OA.
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Affiliation(s)
- M T Murphy
- Department of Rehabilitation Medicine, University of Kansas Medical Center, 3901 Rainbow Boulevard, Mailstop 1046, Kansas City, KS, 66160, USA.
| | - N Wang
- Department of Biostatistics and Epidemiology, Boston University, Boston, MA, USA.
| | - D T Felson
- Department of Epidemiology, Boston University, Boston, MA, USA.
| | - M C Nevitt
- Department of Epidemiology and Biostatistics, University of California-San Francisco, San Francisco, CA, USA.
| | - C E Lewis
- Department of Epidemiology, University of Alabama at Birmingham, Birmingham, AL, USA.
| | - L Frey-Law
- Department of Physical Therapy and Rehabilitation Science, University of Iowa, Iowa City, IA, USA.
| | - A Guermazi
- Department of Radiology, Boston University, Boston, MA, USA.
| | - N A Segal
- Department of Rehabilitation Medicine, University of Kansas Medical Center, 3901 Rainbow Boulevard, Mailstop 1046, Kansas City, KS, 66160, USA.
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Effect of New Zealand Blackcurrant Extract on Force Steadiness of the Quadriceps Femoris Muscle during Sustained Submaximal Isometric Contraction. J Funct Morphol Kinesiol 2022; 7:jfmk7020044. [PMID: 35736015 PMCID: PMC9225559 DOI: 10.3390/jfmk7020044] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Revised: 05/15/2022] [Accepted: 05/27/2022] [Indexed: 11/25/2022] Open
Abstract
Intake of anthocyanin-rich New Zealand blackcurrant (NZBC) can alter physiological responses that enhance exercise performance. In two studies, we examined the effects of NZBC extract on force steadiness during a sustained submaximal isometric contraction of the quadriceps femoris muscle. With repeated measures designs, male participants in study one (n = 13) and study two (n = 19) performed a 120 s submaximal (30%) isometric contraction of the quadriceps femoris muscle following a 7-day intake of NZBC extract and placebo (study one) and following 0 (control), 1-, 4- and 7-day intake of NZBC extract (study two). Participants for both studies were different. In study one, NZBC extract enhanced isometric force steadiness during the 120 s contraction (placebo: 6.58 ± 2.24%, NZBC extract: 6.05 ± 2.24%, p = 0.003), with differences in the third (60-89 s) and fourth quartile (90-120 s) of the contraction. In study two, isometric force steadiness was not changed following 1 and 4 days but was enhanced following 7-day intake of NZBC extract in comparison to control. In study two, the enhanced isometric force steadiness following 7-day intake did occur in the second (30-59 s), third (60-89 s) and fourth (90-120 s) quartiles. Daily supplementation of anthocyanin-rich NZBC extract can enhance force steadiness of the quadriceps femoris muscle during a sustained submaximal isometric contraction. Our observations may have implications for human tasks that require postural stability.
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Ong JH, Simic M, Eisenhuth J, Burns J, Baldwin JN, McKay MJ. Normative Reference Values for Knee Extensor Muscle Rate of Torque Development and Torque Steadiness in Adolescents and Adults. J Clin Rheumatol 2022; 28:155-161. [PMID: 35293889 DOI: 10.1097/rhu.0000000000001819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE The aim of this study was to establish reference values for rate of torque development (RTD) and muscle torque steadiness (MTS) of knee extensors across the lifespan, and evaluate if these measures are independently associated with Osteoarthritis Research Society International (OARSI)-recommended performance-based measures (6-minute walk test, 30-second chair stand test, stair climb test) and other clinical variables. METHODS In this cross-sectional observational study, knee extensor strength of 764 participants (12-89 years) from the 1000 Norms Project was assessed via fixed dynamometry. Age- and sex-stratified normative RTD (Nms-1 kg-1) and MTS (Nm kg-1) values were presented as means and 95% confidence intervals. Correlations and multiple regression analyses were calculated to identify factors (age, sex, height, weight, OARSI-recommended performance-based measures, Knee Injury and Osteoarthritis Outcome Score, vertical jump, long jump, grip strength, basic gait-related knee biomechanics) independently associated with RTD or MTS. RESULTS Age- and sex-stratified normative RTD and MTS reference values were generated. Male subjects exhibited higher RTD but poorer MTS (less steady) than female subjects across all age groups. Better performance in OARSI-recommended performance-based measures, vertical jump, long jump, and grip strength were associated with greater RTD but poorer MTS. Thirty-second chair stand test, stair climb test, vertical jump, long jump, and grip strength were independent determinants of RTD and MTS. CONCLUSIONS The RTD and MTS demonstrated associations with clinical variables relevant to knee osteoarthritis. The normative reference values generated may help identify the presence and extent of impairments in RTD and MTS associated with knee osteoarthritis and assist in developing responsive outcome measures for therapeutic trials.
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Affiliation(s)
- Jia Hui Ong
- From the School of Health Sciences, Faculty of Medicine and Health, The University of Sydney
| | - Milena Simic
- From the School of Health Sciences, Faculty of Medicine and Health, The University of Sydney
| | - John Eisenhuth
- From the School of Health Sciences, Faculty of Medicine and Health, The University of Sydney
| | | | - Jennifer N Baldwin
- Priority Research Centre for Physical Activity and Nutrition, College of Health, Medicine and Wellbeing, The University of Newcastle, Newcastle, Australia
| | - Marnee J McKay
- From the School of Health Sciences, Faculty of Medicine and Health, The University of Sydney
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Tajitsu H, Fukumoto Y, Asai T, Monjo H, Kubo H, Oshima K, Koyama S. Association between knee extensor force steadiness and postural stability against mechanical perturbation in patients with Parkinson’s disease. J Electromyogr Kinesiol 2022; 64:102660. [DOI: 10.1016/j.jelekin.2022.102660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 03/31/2022] [Accepted: 04/08/2022] [Indexed: 11/16/2022] Open
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Labanca L, Rocchi JE, Carta N, Giannini S, Macaluso A. NMES superimposed on movement is equally effective as heavy slow resistance training in patellar tendinopathy. JOURNAL OF MUSCULOSKELETAL & NEURONAL INTERACTIONS 2022; 22:474-485. [PMID: 36458385 PMCID: PMC9716305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
OBJECTIVE This study aimed at investigating the effectiveness of an 8-week training protocol, based on neuromuscular electrical stimulation of the quadriceps, which was superimposed onto voluntary exercise (NMES+), in comparison to a traditional heavy slow resistance training (HSRT), in individuals with patellar tendinopathy. METHODS Thirty-two physically active participants, aged: 33.6±10.2 years, were divided into two groups: NMES+ or HSRT. Maximal voluntary isometric contraction (MVIC) of knee extensor and flexor muscles, power during a countermovement jump (CMJ), and VISA-p questionnaire scores were recorded at the start(T0), 2-weeks(T1), 4-weeks(T2), 6-weeks(T3), 8-weeks(T4) and 4-months post-training (T5). Knee pain and rate of perceived exertion (RPE) were recorded at each training session with a 0-10 scale. RESULTS Knee pain was significantly lower in NMES+ compared to HSRT during all training sessions. No significant between-group differences were found for VISA-p scores and forces recorded during MVICs at T0,T1,T2,T3,T4 and T5. A significant increase of VISA-p and peak forces during MVIC was recorded across-time in both groups. No significant between-group or across-time differences were found for RPE and CMJ parameters. CONCLUSIONS NMES+ and HSRT were equally effective in decreasing tendinopathy symptoms and increasing strength, with NMES+ having the advantage to be a pain-free resistance training modality.
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Affiliation(s)
- Luciana Labanca
- Department of Movement, Human and Health Sciences, University of Rome Foro Italico, Rome, Italy,Corresponding author: Luciana Labanca, PhD, Department of Movement, Human and Health Sciences, University of Rome Foro Italico, Piazza Lauro De Bosis 6, 00135, Roma, Italy E-mail:
| | | | - Nicola Carta
- Villa Stuart Sport Clinic-FIFA Medical Centre of Excellence, Rome, Italy
| | - Silvana Giannini
- Villa Stuart Sport Clinic-FIFA Medical Centre of Excellence, Rome, Italy
| | - Andrea Macaluso
- Department of Movement, Human and Health Sciences, University of Rome Foro Italico, Rome, Italy,Villa Stuart Sport Clinic-FIFA Medical Centre of Excellence, Rome, Italy
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Forestieri Faccio AF, Porto JM, Freire Júnior RC, Medeiros de Oliveira BG, Carvalho de Abreu DC. Trunk muscle function and anterior and posterior limits of stability in community-dwelling older adults. J Bodyw Mov Ther 2021; 28:212-218. [PMID: 34776143 DOI: 10.1016/j.jbmt.2021.06.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 04/08/2021] [Accepted: 06/09/2021] [Indexed: 11/20/2022]
Abstract
BACKGROUND Understanding of the influence of trunk muscles on the older adult's limit of stability (LOS) is important for clinical practice. OBJECTIVE To compare the anterior and posterior LOS and the flexor and extensor trunk muscle function; verify the association of trunk muscles and LOS, and the association of LOS and the previous falls of community-dwelling older adults. METHODS Sample characterization data, trunk muscle function (peak torque - PT and torque steadiness - TS), LOS and previous falls (6 months) were collected from 79 older people. Comparisons were made between the variables of the anterior/posterior LOS (Reaction time, Movement velocity, Maximum excursion, Directional control), between trunk extensors/flexors muscle function and between TS at 10% and at 50%. Associations were made between the anterior/posterior LOS and the number of previous falls and between LOS and trunk muscle function. RESULTS The posterior LOS was worse than the anterior LOS, except for the reaction time. The flexor muscles obtained a lower PT, but better performance in TS. The TS at 10% of the trunk extensor was associated with the posterior directional control (p = 0.032). There was no association between trunk muscle function and the anterior LOS, or between previous falls and LOS. CONCLUSIONS The older adults presented worse performance in the posterior LOS and worse TS in the trunk extensor muscles, although the trunk extensor muscles presented a higher PT. Although no association between LOS and previous falls, the better the TS at 10% of the trunk extensors, better posterior directional control.
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Affiliation(s)
- Andrea Fernanda Forestieri Faccio
- Department of Health Sciences, Rehabilitation and Functional Performance Program, Laboratory of Assessment and Rehabilitation of Equilibrium (L.A.R.E.), Ribeirão Preto Medical School, University of São Paulo, Bandeirantes Avenue, 3900, Ribeirão Preto, SP, 14049-900, Brazil.
| | - Jaqueline Mello Porto
- Department of Health Sciences, Rehabilitation and Functional Performance Program, Laboratory of Assessment and Rehabilitation of Equilibrium (L.A.R.E.), Ribeirão Preto Medical School, University of São Paulo, Bandeirantes Avenue, 3900, Ribeirão Preto, SP, 14049-900, Brazil.
| | - Renato Campos Freire Júnior
- Faculty of Physical Education and Physiotherapy, Federal University of Amazonas (UFAM), General Rodrigo Octávio Avenue, 6200, Manaus, AM, 69080-900, Brazil.
| | - Bruna Garcia Medeiros de Oliveira
- Department of Health Sciences, Rehabilitation and Functional Performance Program, Laboratory of Assessment and Rehabilitation of Equilibrium (L.A.R.E.), Ribeirão Preto Medical School, University of São Paulo, Bandeirantes Avenue, 3900, Ribeirão Preto, SP, 14049-900, Brazil.
| | - Daniela Cristina Carvalho de Abreu
- Department of Health Sciences, Rehabilitation and Functional Performance Program, Laboratory of Assessment and Rehabilitation of Equilibrium (L.A.R.E.), Ribeirão Preto Medical School, University of São Paulo, Bandeirantes Avenue, 3900, Ribeirão Preto, SP, 14049-900, Brazil.
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Tseng SY, Ko CP, Tseng CY, Huang WC, Lai CL, Wang CH. Is 20 Hz Whole-Body Vibration Training Better for Older Individuals than 40 Hz? INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph182211942. [PMID: 34831698 PMCID: PMC8625607 DOI: 10.3390/ijerph182211942] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Revised: 11/04/2021] [Accepted: 11/06/2021] [Indexed: 11/16/2022]
Abstract
In recent years, whole-body vibration (WBV) training has been used as a training method in health promotion. This study attempted to use WBV at three different frequencies (20, 30, and 40 Hz) with subjects from different age groups to analyze the activation of the rectus femoris muscle. The subjects included 47 females and 51 males with an average age of 45.1 ± 15.2 years. Results indicated significant differences in subjects from different age groups at 20 Hz WBV. Muscle contraction was greater in the subjects who were older (F(4,93) = 82.448, p < 0.001). However, at 30 Hz WBV, the difference was not significant (F(4,93) = 2.373, p = 0.058). At 40 Hz WBV, muscle contraction was less in the older subjects than in the younger subjects (F(4,93) = 18.025, p < 0.001). The spectrum analysis also indicated that at 40 Hz there was less muscle activity during WBV in the older subjects than in the younger ones. Therefore, age was found to have a significant effect on muscle activation during WBV at different frequencies. If the training is offered to elderly subjects, their neuromuscular responses to 20 Hz WBV will be more suitable than to 40 Hz WBV.
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Affiliation(s)
- Shiuan-Yu Tseng
- Graduate Institute of Service Industries and Management, Minghsin University of Science and Technology, Hsinchu 30401, Taiwan;
| | - Chung-Po Ko
- Department of Neurosurgery, Tungs’ Taichung MetroHarbor Hospital, Taichung 43503, Taiwan;
| | - Chin-Yen Tseng
- Department of Physical Therapy, Upright Come Scoliosis Clinic, Hsinchu 30286, Taiwan;
| | - Wei-Ching Huang
- Department of Physical Medicine and Rehabilitation, Taichung Hospital, Ministry of Health and Welfare, Taichung 40343, Taiwan;
| | - Chung-Liang Lai
- Department of Occupational Therapy, College of Medical and Health Science, Asia University, Taichung 41354, Taiwan;
- Department of Physical Medicine and Rehabilitation, Puzi Hospital, Ministry of Health and Welfare, Chiayi County 61347, Taiwan
| | - Chun-Hou Wang
- Department of Physical Therapy, Chung Shan Medical University, Taichung 40201, Taiwan
- Physical Therapy Room, Chung Shan Medical University Hospital, Taichung 40201, Taiwan
- Correspondence:
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Rate of Torque Development and Torque Steadiness of the Lower Limb and Future Falls Among Community-Dwelling Older Adults Without Previous Falls: A Longitudinal 1-Year Study. J Aging Phys Act 2021; 30:168-176. [PMID: 34407502 DOI: 10.1123/japa.2020-0442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 02/16/2021] [Accepted: 03/11/2021] [Indexed: 11/18/2022]
Abstract
The objective was to investigate the association between rate of torque development (RTD) and torque steadiness (TS) of the lower limb and the occurrence of prospective falls in community-dwelling older adults without falls in the previous year. One hundred older adults performed the tests to obtain the RTD and TS of the hip, knee, and ankle. New episodes of falls were monitored through telephone contact for a prospective period of 12 months. The association of RTD and TS with the occurrence of prospective falls was verified by multiple logistic regression adjusted for confounding variables. There was no association between RTD of hip, knee, and ankle and prospective falls. Only the TS at 50% of the peak torque of the hip flexors was associated with the occurrence of future falls (p = .023). Identifying modifiable risk factors for the first fall in older adults is essential for the development of adequate prevention programs.
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Characteristics of rectus femoris activation and rectus femoris-hamstrings coactivation during force-matching isometric knee extension in subacute stroke. Exp Brain Res 2021; 239:2621-2633. [PMID: 34213633 DOI: 10.1007/s00221-021-06162-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 06/22/2021] [Indexed: 10/20/2022]
Abstract
The spectral properties of surface electromyographic (EMG) signal in the rectus femoris (RF) and the coactivation in the medial hamstrings (MH) were investigated in 45 stroke subjects (22 ± 12 days post-onset) and 30 age-matched healthy controls who performed unilateral knee extensions at maximum effort (100% MVC) and during 5-s force-matching tasks (10, 30, 50% MVC). The spectral properties were obtained through a power spectrum analysis based on Fast Fourier Transform. The coactivation was measured as the MH amplitude (%max) and MH/RF amplitude ratio. Force variability was expressed as the coefficient of variation. Both knee extensors and flexors were weaker in the paretic leg than the non-paretic and control legs (p < 0.001). A significantly higher relative power in the 5-13 and 13-30 Hz bands was found in the paretic than the non-paretic leg across all force levels (p ≤ 0.001) without changes in the 30-60 and 60-100 Hz bands or the mean and median frequencies. Regarding the antagonist coactivation, MH amplitude in the paretic leg was higher than in the non-paretic leg (submaximal levels, p < 0.0001) and the control leg (all force levels, p = 0.0005) with no differences between legs in the MH/RF ratio. The steadiness of the knee extension force was not related to the spectral properties of the agonist EMG or antagonistic coactivation. Greater coactivation was associated with weaker paretic knee flexors (p ≤ 0.0002). The overall results suggest variably altered agonist activation and antagonistic coactivation over the range of isometric knee extension contractions in subacute stroke.
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Tsatsaki E, Amiridis IG, Holobar A, Trypidakis G, Arabatzi F, Kellis E, Enoka RM. The length of tibialis anterior does not influence force steadiness during submaximal isometric contractions with the dorsiflexors. Eur J Sport Sci 2021; 22:539-548. [PMID: 33899692 DOI: 10.1080/17461391.2021.1922506] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The purpose of the study was to assess the influence of short, intermediate, and long muscle lengths on dorsiflexor force steadiness and the discharge characteristics of motor units in tibialis anterior during submaximal isometric contractions. Steady contractions were performed at 5 target forces (5, 10, 20, 40, and 60% maximal voluntary contraction, MVC) for 3 ankle angles (75°, 90°, and 105°). MVC force was less (p = 0.043) at the smallest joint angle compared with the other two angles. The absolute (standard deviation) and normalised amplitudes (coefficient of variation) of the force fluctuations were similar for all 3 ankle angles at each target force. The coefficient of variation for force decreased progressively from 5% to 20% MVC force and then it plateaued at 40% and 60% MVC force. At all target forces, the mean discharge rate (MDR) of the motor units at 75° was greater than at 90° (p = 0.006) and 105° (p = 0.034). Moreover, the MDR was similar for 5% and 10% MVC forces and then increased gradually until 60% MVC force (p < 0.005). The variability in discharge times (coefficient of variation for interspike interval) and variability in neural drive (coefficient of variation of filtered cumulative spike train) were similar at all ankle angles. Variability in neural drive had a greater influence on force steadiness than did the variability in discharge times. Changes in ankle-joint angle did not influence either the normalised amplitude force fluctuations during steady submaximal contractions or the underlying modulation of the discharge characteristics of motor units in tibialis anterior.
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Affiliation(s)
- Eirini Tsatsaki
- Department of Physical Education and Sport Sciences at Serres, Aristotle University of Thessaloniki, Serres, Greece
| | - Ioannis G Amiridis
- Department of Physical Education and Sport Sciences at Serres, Aristotle University of Thessaloniki, Serres, Greece
| | - Ales Holobar
- Faculty of Electrical Engineering and Computer Science, University of Maribor, Maribor, Slovenia
| | - Georgios Trypidakis
- Department of Physical Education and Sport Sciences at Serres, Aristotle University of Thessaloniki, Serres, Greece
| | - Fotini Arabatzi
- Department of Physical Education and Sport Sciences at Serres, Aristotle University of Thessaloniki, Serres, Greece
| | - Eleftherios Kellis
- Department of Physical Education and Sport Sciences at Serres, Aristotle University of Thessaloniki, Serres, Greece
| | - Roger M Enoka
- Department of Integrative Physiology, University of Colorado, Boulder, CO, USA
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Grooms DR, Criss CR, Simon JE, Haggerty AL, Wohl TR. Neural Correlates of Knee Extension and Flexion Force Control: A Kinetically-Instrumented Neuroimaging Study. Front Hum Neurosci 2021; 14:622637. [PMID: 33613205 PMCID: PMC7890238 DOI: 10.3389/fnhum.2020.622637] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 12/23/2020] [Indexed: 11/13/2022] Open
Abstract
Background: The regulation of muscle force is a vital aspect of sensorimotor control, requiring intricate neural processes. While neural activity associated with upper extremity force control has been documented, extrapolation to lower extremity force control is limited. Knowledge of how the brain regulates force control for knee extension and flexion may provide insights as to how pathology or intervention impacts central control of movement. Objectives: To develop and implement a neuroimaging-compatible force control paradigm for knee extension and flexion. Methods: A magnetic resonance imaging (MRI) safe load cell was used in a customized apparatus to quantify force (N) during neuroimaging (Philips Achieva 3T). Visual biofeedback and a target sinusoidal wave that fluctuated between 0 and 5 N was provided via an MRI-safe virtual reality display. Fifteen right leg dominant female participants (age = 20.3 ± 1.2 years, height = 1.6 ± 0.10 m, weight = 64.8 ± 6.4 kg) completed a knee extension and flexion force matching paradigm during neuroimaging. The force-matching error was calculated based on the difference between the visual target and actual performance. Brain activation patterns were calculated and associated with force-matching error and the difference between quadriceps and hamstring force-matching tasks were evaluated with a mixed-effects model (z > 3.1, p < 0.05, cluster corrected). Results: Knee extension and flexion force-matching tasks increased BOLD signal among cerebellar, sensorimotor, and visual-processing regions. Increased knee extension force-matching error was associated with greater right frontal cortex and left parietal cortex activity and reduced left lingual gyrus activity. Increased knee flexion force-matching error was associated with reduced left frontal and right parietal region activity. Knee flexion force control increased bilateral premotor, secondary somatosensory, and right anterior temporal activity relative to knee extension. The force-matching error was not statistically different between tasks. Conclusion: Lower extremity force control results in unique activation strategies depending on if engaging knee extension or flexion, with knee flexion requiring increased neural activity (BOLD signal) for the same level of force and no difference in relative error. These fMRI compatible force control paradigms allow precise behavioral quantification of motor performance concurrent with brain activity for lower extremity sensorimotor function and may serve as a method for future research to investigate how pathologies affect lower extremity neuromuscular function.
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Affiliation(s)
- Dustin R Grooms
- Ohio Musculoskeletal and Neurological Institute, Ohio University, Grover Center, Athens, OH, United States.,Division of Athletic Training, School of Applied Health Sciences and Wellness, College of Health Sciences and Professions, Ohio University, Grover Center, Athens, OH, United States.,Division of Physical Therapy, School of Rehabilitation and Communication Sciences, College of Health Sciences and Professions, Ohio University, Grover Center, Athens, OH, United States
| | - Cody R Criss
- Ohio Musculoskeletal and Neurological Institute, Ohio University, Grover Center, Athens, OH, United States.,Translational Biomedical Sciences Program, Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, United States
| | - Janet E Simon
- Ohio Musculoskeletal and Neurological Institute, Ohio University, Grover Center, Athens, OH, United States.,Division of Athletic Training, School of Applied Health Sciences and Wellness, College of Health Sciences and Professions, Ohio University, Grover Center, Athens, OH, United States
| | - Adam L Haggerty
- Ohio Musculoskeletal and Neurological Institute, Ohio University, Grover Center, Athens, OH, United States.,Division of Athletic Training, School of Applied Health Sciences and Wellness, College of Health Sciences and Professions, Ohio University, Grover Center, Athens, OH, United States
| | - Timothy R Wohl
- Honors Tutorial College, Ohio University, Athens, OH, United States.,Division of Physical Therapy, School of Health and Rehabilitation Sciences, Ohio State University, Columbus, OH, United States
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23
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Davis LA, Carzoli JP, Feka K, Nelson C, Enoka RM. Exercise with TENS does not augment gains in balance and strength for dancers. J Electromyogr Kinesiol 2020; 56:102507. [PMID: 33249347 DOI: 10.1016/j.jelekin.2020.102507] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 11/11/2020] [Accepted: 11/13/2020] [Indexed: 11/16/2022] Open
Abstract
Electrical stimulation modulates sensory feedback and improves motor performance, at least for individuals with compromised sensorimotor function. The purpose of this study was to determine the effectiveness of a 4-wk intervention with transcutaneous electrical nerve stimulation (TENS) at improving strength and balance in dancers. Nineteen dancers completed a timed, single-leg balance test, the Y-balance test, and contractions with the hip flexor and knee extensor muscles to assess maximal strength and force steadiness. They completed 4-wks of moderate-intensity bodyweight exercises (3x/wk) and were pseudo-randomized to either a Treatment or Sham group in a single-blind design. The Treatment group received constant TENS over the hamstring muscles during the exercises, whereas the Sham group was exposed to a brief TENS current. The data were pooled due to few significant between-group differences from before to after the intervention. Most outcome measures significantly improved: hip extensor muscles were stronger (P ≤ 0.01), time stood on a single-leg with eyes closed increased (P = 0.02), and the distance reached during the Y-balance test increased (P ≤ 0.001). The improvement in scores on the Y-balance test exceeded the minimal clinically significant change. Twelve sessions of moderate-intensity bodyweight exercises improved muscle strength and balance in experienced dancers. The addition of TENS, however, did not augment the gains in function.
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Affiliation(s)
- Leah A Davis
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, USA.
| | - Joseph P Carzoli
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, USA
| | - Kaltrina Feka
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, USA; Health Promotion and Cognitive Sciences, Department of Psychology, Educational Science and Human Movement, University of Palermo, Palermo, Italy
| | - Christina Nelson
- Department of Theater and Dance, University of Colorado Boulder, Boulder, CO, USA
| | - Roger M Enoka
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, USA
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24
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Wu R, Ditroilo M, Delahunt E, De Vito G. Age Related Changes in Motor Function (II). Decline in Motor Performance Outcomes. Int J Sports Med 2020; 42:215-226. [PMID: 33137831 DOI: 10.1055/a-1265-7073] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Age-related impairments in motor performance are caused by a deterioration in mechanical and neuromuscular functions, which have been investigated from the macro-level of muscle-tendon unit to the micro-level of the single muscle fiber. When compared to the healthy young skeletal muscle, aged skeletal muscle is: (1) weaker, slower and less powerful during the performance of voluntary contractions; (2) less steady during the performance of isometric contractions, particularly at low levels of force; and (3) less susceptible to fatigue during the performance of sustained isometric contractions, but more susceptible to fatigue during the performance of high-velocity dynamic contractions. These impairments have been discussed to be mainly the result of: a) loss of muscle mass and selective atrophy of type II muscle fibers; b) altered tendon mechanical properties (decreased tendon stiffness); c) reduced number and altered function of motor units; d) slower muscle fiber shortening velocity; e) increased oscillation in common synaptic input to motor neurons; and f) altered properties and activity of sarcoplasmic reticulum. In this second part of a two-part review we have detailed the age-related impairments in motor performance with a reference to the most important mechanical and neuromuscular contributing factors.
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Affiliation(s)
- Rui Wu
- School of Public Health Physiotherapy and Sports Science, University College Dublin, Dublin
| | - Massimiliano Ditroilo
- School of Public Health Physiotherapy and Sports Science, University College Dublin, Dublin
| | - Eamonn Delahunt
- School of Public Health Physiotherapy and Sports Science, University College Dublin, Dublin
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25
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Porto JM, Spilla SB, Cangussu-Oliveira LM, Freire Júnior RC, Nakaishi APM, de Abreu DCC. Effect of Aging on Trunk Muscle Function and Its Influence on Falls Among Older Adults. J Aging Phys Act 2020; 28:699-706. [PMID: 32303002 DOI: 10.1123/japa.2019-0194] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 01/06/2020] [Accepted: 01/07/2020] [Indexed: 11/18/2022]
Abstract
The objective was to determine whether trunk muscle function is influenced by the aging process and to identify if the trunk can be an important factor in older people's falls over a period of 1 year. The peak torque, rate of torque development, and torque steadiness of the trunk extensors and flexors were compared between a young group, older group (older adults with no episodes of falls), and older faller group (older adults who had suffered at least one fall episode over a period of 1 year) by one-way analysis of variance, followed by the post hoc Tukey test. The adjusted multivariate linear regression was applied to verify the association between the number of falls and the trunk parameters in older adults. The young group showed higher extensors and flexors peak torque and rate of torque development, and lower extensor torque steadiness at 10% when compared with older groups. Only trunk flexor peak torque showed a negative association with the number of future falls (p = .042), but there was no difference in trunk muscle function between the older group and the older faller group.
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26
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Stefanik JJ, Frey-Law L, Segal NA, Niu J, Lewis CE, Nevitt MC, Neogi T. The relation of peripheral and central sensitization to muscle co-contraction: the MOST study. Osteoarthritis Cartilage 2020; 28:1214-1219. [PMID: 32585174 PMCID: PMC7727285 DOI: 10.1016/j.joca.2020.06.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 05/27/2020] [Accepted: 06/12/2020] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To examine the relation of pain sensitization to altered motor activity in knee OA as assessed by hamstrings muscle co-contraction during maximal effort knee extension. DESIGN Medial, lateral, and overall hamstring co-contraction was assessed in the Multicenter Osteoarthritis (MOST) Study cohort using electromyography during isokinetic knee extension at 60°/second. Mechanical temporal summation of pain (TS) was assessed at the right wrist and pressure pain thresholds (PPT) were assessed at the patellae; PPTs were categorized into sex-specific tertiles. Muscle co-contraction was categorized into age- and sex-specific tertiles. We evaluated the relation of measures of sensitization to muscle co-contraction using a generalized logistic regression model. RESULTS 1633 participants were included: mean age and BMI was 67.3 ± 7.7 years and 30.3 ± 5.6 kg/m2, respectively; 58% were female. Presence of TS was associated with higher overall (OR 1.3, 95% confidence interval (CI) (1.0-1.8)), medial (1.4 (1.0-1.9), and lateral (1.3 (1.0, 1.9)) hamstring co-contraction. The lowest PPT tertile (greater sensitivity) was associated with higher overall (1.5 (1.0, 2.3)) and medial (1.5 (1.0, 2.3)) hamstring co-contraction compared with those in the highest PPT tertile. CONCLUSION Greater pain sensitization, as assessed by presence of TS at the wrist and low patellar PPT, was associated with greater overall and medial hamstring co-contraction during knee extension. This provides support to the possibility that peripheral and/or central nervous system alterations may not only affect pain sensitivity, but also motor function.
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Affiliation(s)
- J J Stefanik
- Northeastern University, Boston, MA, USA; Boston University School of Medicine, Boston, MA, USA.
| | | | - N A Segal
- University of Iowa, Iowa City, USA; University of Kansas Medical Center, Kansas City, KS, USA
| | - J Niu
- Baylor College of Medicine, Houston, TX, USA
| | - C E Lewis
- Univerity of Alabama at Birmingham, Birmingham, USA
| | - M C Nevitt
- University of California San Francisco, San Francisco, USA
| | - T Neogi
- Boston University School of Medicine, Boston, MA, USA
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27
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Ueyama H, Kanemoto N, Minoda Y, Taniguchi Y, Nakamura H. 2020 Chitranjan S. Ranawat Award: Perioperative essential amino acid supplementation suppresses rectus femoris muscle atrophy and accelerates early functional recovery following total knee arthroplasty. Bone Joint J 2020; 102-B:10-18. [PMID: 32475274 DOI: 10.1302/0301-620x.102b6.bjj-2019-1370.r1] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
AIMS The aim of this study was to assess the effectiveness of perioperative essential amino acid (EAA) supplementation to prevent rectus femoris muscle atrophy and facilitate early recovery of function after total knee arthroplasty (TKA). METHODS The study involved 60 patients who underwent unilateral TKA for primary knee osteo-arthritis (OA). This was a double-blind, placebo-controlled, randomized control trial with patients randomly allocated to two groups, 30 patients each: the essential amino acid supplementation (9 g daily) and placebo (lactose powder, 9 g daily) groups. Supplementation and placebo were provided from one week before to two weeks after surgery. The area of the rectus femoris muscle were measured by ultrasound imaging one month before surgery and one, two, three, and four weeks postoperatively. The serum albumin level, a visual analogue knee pain score, and mobility were also measured at each time point. The time to recovery of activities of daily living (ADLs) was recorded. Postoperative nutrition and physiotherapy were identical in both groups. RESULTS The mean relative change from baseline was as follows for the amino acid group: 116% in rectus femoris muscle area (71% to 206%); 95% in serum albumin (80% to 115%) and 39% in VAS pain (0% to 100%) at four weeks after surgery. These values in the placebo group were: 97% in muscle area (68 to 155); 89% in serum albumin (71% to 100%) and 56% in VAS pain four weeks after surgery (0% to 100%). All changes were statistically significant (p < 0.05). The mean time to recovery of ADLs was shorter in the amino acid group compared with the placebo group (p = 0.005). CONCLUSION Perioperative essential amino acid supplementation prevents rectus femoris muscle atrophy and accelerates early functional recovery after TKA. Cite this article: Bone Joint J 2020;102-B(6 Supple A):10-18.
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Affiliation(s)
- Hideki Ueyama
- Department of Orthopaedic Surgery, Osaka City University Graduate School of Medicine, Osaka, Japan, Department of Orthopaedic Surgery, Tanabe Central Hospital, Wakayama, Japan
| | - Narihiro Kanemoto
- Department of Orthopaedic Surgery, Tanabe Central Hospital, Wakayama, Japan
| | - Yukihide Minoda
- Department of Orthopaedic Surgery, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Yoshiki Taniguchi
- Department of Orthopaedic Surgery, Tanabe Central Hospital, Wakayama, Japan
| | - Hiroaki Nakamura
- Department of Orthopaedic Surgery, Osaka City University Graduate School of Medicine, Osaka, Japan
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28
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Wu R, Delahunt E, Ditroilo M, Lowery MM, Segurado R, De Vito G. Changes in knee joint angle affect torque steadiness differently in young and older individuals. J Electromyogr Kinesiol 2019; 47:49-56. [DOI: 10.1016/j.jelekin.2019.05.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 05/13/2019] [Accepted: 05/13/2019] [Indexed: 12/01/2022] Open
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29
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Le Berre M, Morin M, Corriveau H, Hamel M, Nadeau S, Filiatrault J, Dumoulin C. Characteristics of Lower Limb Muscle Strength, Balance, Mobility, and Function in Older Women with Urge and Mixed Urinary Incontinence: An Observational Pilot Study. Physiother Can 2019; 71:250-260. [PMID: 31719721 DOI: 10.3138/ptc.2018-30] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Purpose: After the age of 65, urinary incontinence (UI) occurs in one of every two women. A positive correlation between falls and urgency UI (UUI) or mixed UI (MUI) has also been identified. However, lower extremity impairments in older women with UUI or MUI have not been thoroughly investigated. The primary goal of this study was to compare lower limb strength, balance, mobility, and function in older women with and without UUI or MUI. The secondary goal was to evaluate the association between these measurements and UI severity. Method: A total of 40 older women with and without UUI or MUI completed standardized tests for lower limb strength (knee flexor or extensor dynamometry, 30-second sit-to-stand test), balance (single-leg stance test, Four Square Step Test, Activities-specific Balance Confidence questionnaire), mobility (10-metre walk test, 6-minute walk test), and function (Human Activity Profile questionnaire, 12-Item Short Form Health Survey). Results: Significant differences in balance and mobility were observed between the two groups. Women with UI had shorter single-leg stance times, lower balance confidence scores, and slower gait speeds. Conclusions: The results from this pilot study suggest that high-functioning older women with UUI or MUI have balance and mobility impairments. More studies are needed to confirm these results. By reporting power calculations for sample size, this pilot study provides a useful basis on which to design and conduct larger studies.
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Affiliation(s)
- Mélanie Le Berre
- Institut Universitaire de Gériatrie de Montréal.,School of Rehabilitation, Université de Montréal
| | - Mélanie Morin
- School of Rehabilitation, Université de Sherbrooke, Sherbrooke, Que
| | - Hélène Corriveau
- School of Rehabilitation, Université de Sherbrooke, Sherbrooke, Que
| | - Mathieu Hamel
- School of Rehabilitation, Université de Sherbrooke, Sherbrooke, Que
| | - Sylvie Nadeau
- School of Rehabilitation, Université de Montréal.,Pathokinesiology Laboratory, Centre for Interdisciplinary Research in Rehabilitation of Greater Montreal, Montreal
| | - Johanne Filiatrault
- Institut Universitaire de Gériatrie de Montréal.,School of Rehabilitation, Université de Montréal
| | - Chantale Dumoulin
- Institut Universitaire de Gériatrie de Montréal.,School of Rehabilitation, Université de Montréal
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30
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Zellmer M, Kernozek TW, Gheidi N, Hove J, Torry M. Patellar tendon stress between two variations of the forward step lunge. JOURNAL OF SPORT AND HEALTH SCIENCE 2019; 8:235-241. [PMID: 31193251 PMCID: PMC6523035 DOI: 10.1016/j.jshs.2016.12.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 08/23/2016] [Accepted: 10/08/2016] [Indexed: 06/09/2023]
Abstract
BACKGROUND Patellar tendinopathy (PT) or "jumper's knee" is generally found in active populations that perform jumping activities. Graded exposure of patellar tendon stress through functional exercise has been demonstrated to be effective for the treatment of PT. However, no studies have compared how anterior knee displacement variations during the commonly performed forward step lunge (FSL) affect patellar tendon stress. METHODS Twenty-five subjects (age: 22.69 ± 0.74 years; height: 169.39 ± 6.44 cm; mass: 61.55 ± 9.74 kg) performed 2 variations of an FSL with the anterior knee motion going in front of the toes (FSL-FT) and the knee remaining behind the toes (FSL-BT). Kinematic and kinetic data were used with an inverse-dynamics based static optimization technique to estimate individual muscle forces to determine patellar tendon stress during both lunge techniques. A repeated measures multivariate analysis was used to analyze these data. RESULTS The peak patellar tendon stress, stress impulse, quadriceps force, knee moment, knee flexion, and ankle dorsiflexion angle were significantly greater (p < 0.001) during the FSL-FT as compared to the FSL-BT. The peak patellar tendon stress rate did not differ between the FSL-FT and FSL-BT. CONCLUSION The use of an FSL-FT as compared to an FSL-BT increased the load and stress on the patellar tendon. Because a graded exposure of patellar tendon loading with other closed kinetic chain exercises has proven to be effective in treating PT, consideration for the prescription of variations of the FSL and further clinical evaluation of this exercise is warranted in individuals with PT.
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Affiliation(s)
- Matthew Zellmer
- La Crosse Institute for Movement Science, Physical Therapy Program, Department of Health Professions, University of Wisconsin–La Crosse, La Crosse, WI 54601, USA
| | - Thomas W. Kernozek
- La Crosse Institute for Movement Science, Physical Therapy Program, Department of Health Professions, University of Wisconsin–La Crosse, La Crosse, WI 54601, USA
| | - Naghmeh Gheidi
- La Crosse Institute for Movement Science, Physical Therapy Program, Department of Health Professions, University of Wisconsin–La Crosse, La Crosse, WI 54601, USA
| | - Jordan Hove
- La Crosse Institute for Movement Science, Physical Therapy Program, Department of Health Professions, University of Wisconsin–La Crosse, La Crosse, WI 54601, USA
| | - Michael Torry
- Department of Kinesiology and Recreation, Illinois State University, Normal, IL 61761, USA
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31
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Avrillon S, Hug F, Guilhem G. Between-muscle differences in coactivation assessed using elastography. J Electromyogr Kinesiol 2018; 43:88-94. [DOI: 10.1016/j.jelekin.2018.09.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 09/11/2018] [Accepted: 09/20/2018] [Indexed: 01/03/2023] Open
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32
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San Martín-Mohr C, Cristi-Sánchez I, Pincheira PA, Reyes A, Berral FJ, Oyarzo C. Knee sensorimotor control following anterior cruciate ligament reconstruction: A comparison between reconstruction techniques. PLoS One 2018; 13:e0205658. [PMID: 30439952 PMCID: PMC6237303 DOI: 10.1371/journal.pone.0205658] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 09/29/2018] [Indexed: 12/18/2022] Open
Abstract
The sensorimotor system helps to maintain functional joint stability during movement. After anterior cruciate ligament (ACL) injury and reconstruction, several sensorimotor deficits may arise, including altered proprioception and changes in neuromuscular control. It is still unknown whether the type of autograft used in the reconstruction may influence knee sensorimotor impairments. The aim of this study was to comparatively assess the effects of the hamstring tendon (HT) and bone-patellar tendon-bone (BPTB) ACL reconstruction techniques on knee sensorimotor control 6–12 months post-operation. A total of 83 male subjects participated in this study: 27 healthy participants, 30 BPTB-operated patients and 26 HT-operated patients. Active joint position sense in 3 ranges of motion (90–60°, 60–30°, and 30–0° of knee flexion), isometric steadiness, and onset of muscle activation were used to compare sensorimotor system function between groups. Both operated groups had a small (< 5°) but significant joint position sense error in the 30–0° range when compared to the healthy group. No significant differences were found between the operated and the control groups for isometric steadiness or onset of muscle activation. The results of this study suggest that operated patients present knee proprioceptive deficits independently of surgical technique. Nevertheless, the clinical implications of this impairment are still unknown. It seems that selected surgical approach for ACL reconstruction do not affect functioning of the sensorimotor system to a large degree.
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Affiliation(s)
- Cristóbal San Martín-Mohr
- Carrera de Kinesiología, Departamento Ciencias de la salud, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
- Clínica MEDS, Santiago, Chile
- * E-mail:
| | - Iver Cristi-Sánchez
- Clínica MEDS, Santiago, Chile
- Escuela de Kinesiología, Facultad de Ciencias, Universidad Mayor, Santiago, Chile
| | - Patricio A. Pincheira
- Escuela de Kinesiología, Facultad de Ciencias, Universidad Mayor, Santiago, Chile
- Laboratorio Integrativo Biomecánica y Fisiología del Ejercicio, Escuela de Kinesiología, Universidad de los Andes, Santiago, Chile
- School of Human Movement and Nutrition Sciences, The University of Queensland, Brisbane, Australia
| | - Alvaro Reyes
- Facultad de Ciencias de la Rehabilitación, Universidad Andrés Bello, Santiago, Chile
| | | | - Claudio Oyarzo
- Clínica MEDS, Santiago, Chile
- Universidad de Los Andes, Santiago, Chile
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33
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Leung H, Latella C, Lamon S, Hendy AM. The Reliability of Neurological Measurement in the Vastus Medialis: Implications for Research and Practice. Front Psychol 2018; 9:1857. [PMID: 30327634 PMCID: PMC6174212 DOI: 10.3389/fpsyg.2018.01857] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 09/11/2018] [Indexed: 11/21/2022] Open
Abstract
The integrity of the corticomotor pathway is paramount in the optimal functioning of skeletal muscle. However, variability of neurophysiological assessment via peripheral nerve and transcranial magnetic stimulation can render interpretation difficult. Seldom evidence exists regarding the reliability of such measurements in the leg extensors, which have important locomotive and functional roles. This study aimed to assess the test-retest reliability of peripheral, corticospinal and intracortical responses in the vastus medialis. Transcranial magnetic and direct current electrical nerve stimulation were delivered to sixteen healthy young adults (8M and 8F) on two separate occasions. The Hoffmann reflex, maximal compound wave, motor evoked potential, corticospinal silent period, intracortical facilitation, and short-interval intracortical inhibition were recorded from the vastus medialis at rest, and during controlled submaximal voluntary contraction. Relative reliability was quantified using intra-class correlation coefficient (ICC2,1). Absolute reliability was quantified using standard error of measurement (SEm) and minimal detectable change (MDC). Corticospinal silent period, corticospinal silent period/motor evoked potential ratio, active motor evoked potential, maximal Hoffman reflex, and passive short-interval intracortical inhibition demonstrated “good to excellent” relative reliability (ICC ≥ 0.643). Intracortical facilitation demonstrated the lowest relative reliability (ICC = 0.420–0.908). Corticospinal silent period displayed the lowest absolute reliability (SEm ≤ 18.68%). Good reliability of the maximal compound wave, Hoffman reflex, motor evoked potential, and corticospinal silent period allow for reliable neurological evaluation of peripheral and corticospinal pathways in the vastus medialis. Future research should investigate reliability of the intracortical (short-interval intracortical inhibition and intracortical facilitation) measures by using different paired-pulse stimulus parameters. These findings hold important implications for neurophysiological assessment conducted in the leg extensor group.
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Affiliation(s)
- Hans Leung
- School of Exercise and Nutrition Sciences, Institute for Physical Activity and Nutrition (IPAN), Deakin University, Geelong, VIC, Australia
| | - Christopher Latella
- School of Exercise and Nutrition Sciences, Institute for Physical Activity and Nutrition (IPAN), Deakin University, Geelong, VIC, Australia
| | - Séverine Lamon
- School of Exercise and Nutrition Sciences, Institute for Physical Activity and Nutrition (IPAN), Deakin University, Geelong, VIC, Australia
| | - Ashlee M Hendy
- School of Exercise and Nutrition Sciences, Institute for Physical Activity and Nutrition (IPAN), Deakin University, Geelong, VIC, Australia
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34
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Begovic H, Can F, Yağcioğlu S, Ozturk N. Passive stretching-induced changes detected during voluntary muscle contractions. Physiother Theory Pract 2018; 36:731-740. [PMID: 30015563 DOI: 10.1080/09593985.2018.1491660] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Stretching exercises are known for reduction of musculoskeletal stiffness and elongation of electromechanical delay (EMD). However, computing a change in stiffness by means of time delays, detected between onset of electromyographic (EMG), mechanomyographic (MMG) and force signals, can reveal changes in subcomponents (Δt EMG-MMG and Δt MMG-FORCE) of EMD after stretching. In our study, the effect of stretching was investigated while quadriceps femoris (QF) muscle performed isometric contractions. The EMG, MMG, and Force signals were recorded from rectus femoris (RF) and vastus medialis (VM) during five voluntarily isometric contractions at 15°, 30°, and 45° of knee flexion angle, while the leg was positioned on a custom-made device. Subjects in both intervention and control groups underwent same recording procedure before and after stretching. No difference between the baseline repeated contractions (before stretching) was ensured by ANOVA for repeated measures while a difference between PRE and POST was analyzed and concluded based on the effect size results. The EMD did not change; however, subcomponents (Δt EMG-MMG and Δt MMG-FORCE) showed differences within RF and VM muscles after stretching. The 30° knee flexion angle appears to be a position where isometric contraction intensity needs to be carefully monitored during rehabilitation period.
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Affiliation(s)
- Haris Begovic
- Department of Physical Therapy and Rehabilitation, Hacettepe University , Ankara, Turkey.,Department of Biomedical Engineering, Hong Kong Polytechnic University , Hong Kong
| | - Filiz Can
- Department of Physical Therapy and Rehabilitation, Hacettepe University , Ankara, Turkey
| | - Suha Yağcioğlu
- Department of Biophysics, Faculty of Medicine, Hacettepe University , Ankara, Turkey
| | - Necla Ozturk
- Department of Biophysics, Faculty of Medicine, Maltepe University , Istanbul, Turkey
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Latella C, Hendy A, Vanderwesthuizen D, Teo WP. The modulation of corticospinal excitability and inhibition following acute resistance exercise in males and females. Eur J Sport Sci 2018; 18:984-993. [DOI: 10.1080/17461391.2018.1467489] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Affiliation(s)
- Christopher Latella
- School of Medical and Health Sciences, Edith Cowan University, Joondalup, Australia
| | - Ashlee Hendy
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Burwood, Australia
| | - Dan Vanderwesthuizen
- Clinical Exercise Science & Rehabilitation, Institute of Sport, Exercise and Active Living (ISEAL), Victoria University, Footscray, Australia
| | - Wei-Peng Teo
- Institute for Physical Activity and Nutrition (IPAN), School of Exercise and Nutrition Sciences, Deakin University, Burwood, Australia
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Wu R, Delahunt E, Ditroilo M, Lowery MM, DE Vito G. Effect of Knee Joint Angle and Contraction Intensity on Hamstrings Coactivation. Med Sci Sports Exerc 2018; 49:1668-1676. [PMID: 28350712 DOI: 10.1249/mss.0000000000001273] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE This study investigated the effect of knee joint angle and contraction intensity on the coactivation of the hamstring muscles (when acting as antagonists to the quadriceps) in young and older individuals of both sexes. METHODS A total of 25 young (24 ± 2.6 yr) and 26 older (70 ± 2.5 yr) healthy men and women participated. Maximal voluntary isometric contraction of the knee extensors and flexors was assessed at two knee joint angles (90° and 60°, 0° = full extension). At each angle, participants performed submaximal contractions of the knee extensors (20%, 50%, and 80% maximal voluntary isometric contraction), whereas surface EMG was simultaneously acquired from the vastus lateralis and biceps femoris muscles to assess the level (EMG root-mean-square) of agonist activation and antagonist coactivation. Subcutaneous adipose tissue in the areas corresponding to surface EMG electrode placements was measured via ultrasonography. RESULTS The contractions performed at 90° knee flexion demonstrated higher levels of antagonist coactivation (all P < 0.01) and agonist activation (all P < 0.01) as a function of contraction intensity compared with the 60° knee flexion. Furthermore, after controlling for subcutaneous adipose tissue, older participants exhibited a higher level of antagonist coactivation at 60° knee flexion compared with young participants (P < 0.05). CONCLUSIONS The results of the present study suggest that 1) the antagonist coactivation is dependent on knee joint angle and contraction intensity and 2) subcutaneous adipose tissue may affect the measured coactivation level likely because of a cross-talk effect. Antagonist coactivation may play a protective role in stabilizing the knee joint and maintaining constant motor output.
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Affiliation(s)
- Rui Wu
- 1School of Public Health, Physiotherapy and Sports Science, University College Dublin, Dublin, IRELAND; 2Institute for Sport and Health, University College Dublin, Dublin, IRELAND; and 3School of Electrical, Electronic Communications Engineering, University College Dublin, Dublin, IRELAND
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Re-Evaluating Electromyogram–Force Relation in Healthy Biceps Brachii Muscles Using Complexity Measures. ENTROPY 2017. [DOI: 10.3390/e19110624] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Latella C, Teo WP, Harris D, Major B, VanderWesthuizen D, Hendy AM. Effects of acute resistance training modality on corticospinal excitability, intra-cortical and neuromuscular responses. Eur J Appl Physiol 2017; 117:2211-2224. [DOI: 10.1007/s00421-017-3709-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Accepted: 08/13/2017] [Indexed: 01/01/2023]
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Cavanaugh MT, Aboodarda SJ, Behm DG. Intrasession and Intersession Reliability of Quadriceps' and Hamstrings' Electromyography During a Standardized Hurdle Jump Test With Single Leg Landing. J Strength Cond Res 2017; 31:1601-1609. [PMID: 28538311 DOI: 10.1519/jsc.0000000000001631] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The objective of this study was to develop a standardized test to determine quadriceps and hamstrings muscle activation in a position emulating a noncontact anterior cruciate ligament injury. We assessed the intrasession and intersession reliability of surface electromyography (EMG) of the dominant leg after single-leg landing from a standardized hurdle jump. Eighteen subjects (10 males, 8 females) participated in 4 repeated sessions. During each session, individuals performed 3 successful jumps over a hurdle set to 75% of their maximal countermovement jump height and landed on their dominant leg. A jump was only considered successful if the individual could maintain the landing position for longer than 2 seconds after initial ground contact. In one of the 4 sessions, subjects were tested again after a 4-minute rest. The activation of the vastus lateralis (VL), vastus medialis (VM), and biceps femoris (BF), were examined by quantifying the root mean squared (RMS) EMG for 2 seconds immediately after the initial contact. Data from all 3 successful jumps were used to generate intraclass correlation coefficients (ICC), which were then used to determine intrasession and intersession reliability of surface EMG for each muscle. Intrasession reliability was excellent with ICC values of 0.96, 0.94, and 0.93 for the VL, VM, and BF, respectively. Additionally, intersession ICCs were 0.92 (VL), 0.95 (VM), and 0.94 (BF). The standardized hurdle jump with single-leg landing seemed to be a reliable technique for measuring muscle activation for 3 muscles that contribute to knee stabilization.
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Affiliation(s)
- Mark T Cavanaugh
- School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, Newfoundland, Canada
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40
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Effect of constant, predictable, and unpredictable motor tasks on motor performance and blood markers of stress. Exp Brain Res 2017; 235:1323-1336. [PMID: 28204862 DOI: 10.1007/s00221-017-4894-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 01/24/2017] [Indexed: 12/25/2022]
Abstract
An unfamiliar or novel physical stimulus induces activation of dopaminergic neurons within the brain and greater activity in areas involved in emotion; considering this, we aimed to establish whether unpredictable prolonged (fatiguing) motor task (vs. constant vs. predictable) evokes greater dopaminergic activity, enhances neuromuscular performance, motor accuracy, and perception of effort, and delays overall central fatigue. Fifteen healthy male volunteers (aged 22 ± 4 years) were required to perform 1 of 3 exercise trials (at least 1 week apart) of 100 intermittent isometric contraction (IIC) tasks involving knee extensions at 60° flexion. Trials were structured differently by simulated contraction intensity. A fatigue task involved 5-s contractions and 20-s rest. Variables measured before, during, and after IIC were electrically induced force, maximal voluntary contraction, central activation ratio, intramuscular temperature, and blood levels of dopamine, cortisol, and prolactin, and intraindividual motor variability and accuracy (constant and absolute error). We found that IIC increased central and peripheral fatigue, force sensation, and T mu, and decreased absolute and constant error without visual feedback, but did not affect motor variability. There were no significant differences between the three IIC tasks. However, only unpredictable tasks increased dopaminergic activity, which was insufficient to affect central motivation to perform isometric exercise and alter centrally mediated components of fatigue.
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Santos GL, García-Salazar LF, Souza MB, Oliveira AB, Camargo PR, Russo TL. Torque steadiness and muscle activation are bilaterally impaired during shoulder abduction and flexion in chronic post-stroke subjects. J Electromyogr Kinesiol 2016; 30:151-60. [PMID: 27451360 DOI: 10.1016/j.jelekin.2016.07.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 06/30/2016] [Accepted: 07/05/2016] [Indexed: 01/05/2023] Open
Abstract
OBJECTIVE To characterize sensorimotor control and muscle activation in the shoulder of chronic hemiparetic during abduction and flexion in maximal and submaximal isometric contractions. Furthermore, to correlate submaximal sensorimotor control with motor impairment and degree of shoulder subluxation. METHODS Thirteen chronic hemiparetic post-stroke age-gender matched with healthy were included. Isometric torques were assessed using a dynamometer. Electromyographic activity of the anterior and middle deltoid, upper trapezius, pectoralis major and serratus anterior muscles were collected. Variables were calculated for torque: peak, time to target, standard deviation (SD), coefficient of variation (CV), and standard error (RMSE); for muscle activity: maximum and minimum values, range and coefficient of activation. Motor impairment was determined by Fugl-Meyer and shoulder subluxation was measured with a caliper. RESULTS Paretic and non-paretic limbs reduced peak and muscle activation during maximal isometric contraction. Paretic limb generated lower force when compared with non-paretic and control. Paretic and non-paretic presented higher values of SD, CV, RMSE, and CV for prime mover muscles and minimum values for all muscles during steadiness. No correlation was found between sensorimotor control, motor impairment and shoulder subluxation. CONCLUSION Chronic hemiparetic presented bilateral deficits in sensorimotor and muscle control during maximal and submaximal shoulder abduction and flexion.
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Affiliation(s)
- Gabriela Lopes Santos
- Department of Physiotherapy, Federal University of São Carlos (UFSCar), São Carlos, SP, Brazil.
| | - Luisa Fernanda García-Salazar
- Department of Physiotherapy, Federal University of São Carlos (UFSCar), São Carlos, SP, Brazil; Physical Therapy Program, School of Medicine and Health Science, University of Rosario, Bogotá, D.C., Colombia
| | - Matheus Bragança Souza
- Department of Physiotherapy, Federal University of São Carlos (UFSCar), São Carlos, SP, Brazil
| | - Ana Beatriz Oliveira
- Department of Physiotherapy, Federal University of São Carlos (UFSCar), São Carlos, SP, Brazil
| | - Paula Rezende Camargo
- Department of Physiotherapy, Federal University of São Carlos (UFSCar), São Carlos, SP, Brazil
| | - Thiago Luiz Russo
- Department of Physiotherapy, Federal University of São Carlos (UFSCar), São Carlos, SP, Brazil
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Ward S, Bryant AL, Pietrosimone B, Bennell KL, Clark R, Pearce AJ. Cortical motor representation of the rectus femoris does not differ between the left and right hemisphere. J Electromyogr Kinesiol 2016; 28:46-52. [PMID: 26999234 DOI: 10.1016/j.jelekin.2016.03.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Revised: 02/16/2016] [Accepted: 03/07/2016] [Indexed: 11/25/2022] Open
Abstract
Transcranial magnetic stimulation (TMS) involves non-invasive magnetic stimulation of the brain, and can be used to explore the corticomotor excitability and motor representations of skeletal muscles. However there is a lack of motor mapping studies in the lower limb and few conducted in healthy cohorts. The cortical motor representations of muscles can vary between individuals in terms of center position and area despite having a general localized region within the motor cortex. It is important to characterize the normal range for these variables in healthy cohorts to be able to evaluate changes in clinical populations. TMS was used in this cross-sectional study to assess the active motor threshold (AMT) and cortical representation area for rectus femoris in 15 healthy individuals (11M/4F 27.3±5.9years). No differences were found between hemispheres (Left vs. Right P=0.130) for AMT. In terms of y-axis center position no differences were found between hemispheres (Left vs. Right P=0.539), or for the x-axis center position (Left vs. Right P=0.076). Similarly, no differences in calculated area of the motor representation were found (Left vs. Right P=0.699) indicating symmetry between hemispheres.
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Affiliation(s)
- Sarah Ward
- Centre for Health, Exercise and Sports Medicine, Department of Physiotherapy, Faculty of Medicine, Dentistry and Health Science, University of Melbourne, VIC, Australia.
| | - Adam L Bryant
- Centre for Health, Exercise and Sports Medicine, Department of Physiotherapy, Faculty of Medicine, Dentistry and Health Science, University of Melbourne, VIC, Australia
| | - Brian Pietrosimone
- Department of Exercise and Sport Science, University of North Carolina at Chapel Hill, NC, United States
| | - Kim L Bennell
- Centre for Health, Exercise and Sports Medicine, Department of Physiotherapy, Faculty of Medicine, Dentistry and Health Science, University of Melbourne, VIC, Australia
| | - Ross Clark
- School of Exercise Science, Australian Catholic University, VIC, Australia
| | - Alan J Pearce
- Centre for Health, Exercise and Sports Medicine, Department of Physiotherapy, Faculty of Medicine, Dentistry and Health Science, University of Melbourne, VIC, Australia
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Girard O, Brocherie F, Millet GP. High Altitude Increases Alteration in Maximal Torque but Not in Rapid Torque Development in Knee Extensors after Repeated Treadmill Sprinting. Front Physiol 2016; 7:97. [PMID: 27014095 PMCID: PMC4789550 DOI: 10.3389/fphys.2016.00097] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 02/29/2016] [Indexed: 12/05/2022] Open
Abstract
We assessed knee extensor neuromuscular adjustments following repeated treadmill sprints in different normobaric hypoxia conditions, with special reference to rapid muscle torque production capacity. Thirteen team- and racquet-sport athletes undertook 8 × 5-s “all-out” sprints (passive recovery = 25 s) on a non-motorized treadmill in normoxia (NM; FiO2 = 20.9%), at low (LA; FiO2 = 16.8%) and high (HA; FiO2 = 13.3%) normobaric hypoxia (simulated altitudes of ~1800 m and ~3600 m, respectively). Explosive (~1 s; “fast” instruction) and maximal (~5 s; “hard” instruction) voluntary isometric contractions (MVC) of the knee extensors (KE), with concurrent electromyographic (EMG) activity recordings of the vastus lateralis (VL) and rectus femoris (RF) muscles, were performed before and 1-min post-exercise. Rate of torque development (RTD) and EMG (i.e., Root Mean Square or RMS) rise from 0 to 30, −50, −100, and −200 ms were recorded, and were also normalized to maximal torque and EMG values, respectively. Distance covered during the first 5-s sprint was similar (P > 0.05) in all conditions. A larger (P < 0.05) sprint decrement score and a shorter (P < 0.05) cumulated distance covered over the eight sprints occurred in HA (−8 ± 4% and 178 ± 11 m) but not in LA (−7 ± 3% and 181 ± 10 m) compared to NM (−5 ± 2% and 183 ± 9 m). Compared to NM (−9 ± 7%), a larger (P < 0.05) reduction in MVC torque occurred post-exercise in HA (−14 ± 9%) but not in LA (-12 ± 7%), with no difference between NM and LA (P > 0.05). Irrespectively of condition (P > 0.05), peak RTD (−6 ± 11%; P < 0.05), and normalized peak RMS activity for VL (−8 ± 11%; P = 0.07) and RF (−14 ± 11%; P < 0.01) muscles were reduced post-exercise, whereas reductions (P < 0.05) in absolute RTD occurred within the 0–100 (−8 ± 9%) and 0–200 ms (−10 ± 8%) epochs after contraction onset. After normalization to MVC torque, there was no difference in RTD values. Additionally, the EMG rise for VL muscle was similar (P > 0.05), whereas it increased (P < 0.05) for RF muscle during all epochs post-exercise, independently of the conditions. In summary, alteration in repeated-sprint ability and post-exercise MVC decrease were greater at high altitude than in normoxia or at low altitude. However, the post-exercise alterations in RTD were similar between normoxia and low-to-high hypoxia.
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Affiliation(s)
- Olivier Girard
- ISSUL, Institute of Sport Sciences, Faculty of Biology and Medicine, University of LausanneLausanne, Switzerland; Athlete Health and Performance Research Centre, Orthopaedic and Sports Medicine HospitalAspetar, Doha, Qatar
| | - Franck Brocherie
- ISSUL, Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne Lausanne, Switzerland
| | - Grégoire P Millet
- ISSUL, Institute of Sport Sciences, Faculty of Biology and Medicine, University of Lausanne Lausanne, Switzerland
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Schmitt LC, Paterno MV, Ford KR, Myer GD, Hewett TE. Strength Asymmetry and Landing Mechanics at Return to Sport after Anterior Cruciate Ligament Reconstruction. Med Sci Sports Exerc 2016; 47:1426-34. [PMID: 25373481 DOI: 10.1249/mss.0000000000000560] [Citation(s) in RCA: 209] [Impact Index Per Article: 26.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE Evidence-based quadriceps femoris muscle (QF) strength guidelines for return to sport after anterior cruciate ligament (ACL) reconstruction are lacking. This study investigated the effect of QF strength asymmetry on knee landing biomechanics at the time of return to sport after ACL reconstruction. METHODS Seventy-seven individuals (17.4 yr) at the time of return to sport after primary ACL reconstruction (ACLR group) and 47 uninjured control individuals (17.0 yr; CTRL group) participated. QF strength was assessed and quadriceps index was calculated (QI = [involved strength / uninvolved strength] × 100%). The ACLR group was subdivided based on QI: high quadriceps (HQ, QI ≥ 90%) and low quadriceps (LQ, QI < 85%). Knee kinematic and kinetic variables were collected during a drop vertical jump maneuver. Limb symmetry during landing and discrete variables were compared among the groups using multivariate analysis of variance and linear regression analyses. RESULTS The LQ group demonstrated worse asymmetry in all kinetic and ground reaction force variables compared to the HQ and CTRL groups, including reduced involved limb peak knee external flexion moments (P < 0.001), reduced involved limb (P = 0.003) and increased uninvolved limb (P = 0.005) peak vertical ground reaction forces and higher uninvolved limb peak loading rates (P < 0.004). There were no differences in the landing patterns between the HQ and CTRL groups on any variable (P > 0.05). In the ACLR group, QF strength estimated limb symmetry during landing after controlling for graft type, meniscus injury, knee pain, and symptoms. CONCLUSIONS At the time of return to sport, individuals after ACL reconstruction with weaker QF demonstrate altered landing patterns. Conversely, those with nearly symmetrical QF strength demonstrate landing patterns similar to uninjured individuals. Consideration of an objective QF strength measure may aid clinical decision making to optimize sports participation after ACL reconstruction.
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Affiliation(s)
- Laura C Schmitt
- 1Division of Physical Therapy, School of Health and Rehabilitation Sciences, Ohio State University, Columbus, OH; 2Division of Sports Medicine, Cincinnati Children's Hospital Medical Center, Cincinnati, OH; 3Sports Medicine Biodynamics Center and Human Performance Laboratory, Cincinnati Children's Hospital Medical Center, Cincinnati, OH; 4Division of Occupational Therapy and Physical Therapy Cincinnati Children's Hospital Medical Center, Cincinnati, OH; 5Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH; 6Department of Physical Therapy, High Point University, High Point, NC; 7Department of Orthopaedic Surgery, University of Cincinnati, Cincinnati, OH; 8Sports Health & Performance Institute, Ohio State University, Columbus, OH; 9Department of Physiology and Cell Biology, Ohio State University, Columbus, OH; 10Department of Orthopaedic Surgery, Ohio State University, Columbus, OH; 11Department of Family Medicine, Ohio State University, Columbus, OH; 12Department of Biomedical Engineering, Ohio State University, Columbus, OH; and 13School of Health and Rehabilitation Sciences, College of Medicine, Ohio State University, Columbus, OH
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Chung-Hoon K, Tracy BL, Dibble LE, Marcus RL, Burgess P, LaStayo PC. The Association Between Knee Extensor Force Steadiness, Force Accuracy, and Mobility in Older Adults Who Have Fallen. J Geriatr Phys Ther 2016; 39:1-7. [PMID: 25695470 PMCID: PMC4540703 DOI: 10.1519/jpt.0000000000000044] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
BACKGROUND Older adults often experience limited mobility, lower extremity muscle weakness, and increased fall risk. Furthermore, when older adults perform tasks that require control of submaximal force, impairments in their ability to maintain steady and accurate force output have been reported. Such problems may be related to deteriorating levels of mobility, particularly in older adults who have fallen. PURPOSE The purpose of this study was to determine whether an association exists between muscle force steadiness (MFS) or muscle force accuracy (MFA) of the knee extensors and mobility in older adults who have fallen. METHODS Twenty older adults ((Equation is included in full-text article.)= 77.5 ± 7 years, 5 males and 15 females) with 2 or more comorbid conditions and who experienced a fall in the past year underwent assessment of maximal voluntary isometric contraction of the knee extensors. A submaximal target force of 50% of their maximal voluntary isometric contraction was used to determine concentric and eccentric (ECC) steadiness (the fluctuations in force production) and accuracy (the average distance of the mean force from the target force) measures. Mobility was indicated by the 6-minute walk test, the Timed Up and Go, stair ascent, and stair descent tests. Correlation analysis was used to assess the relationship between measures of muscle force control and mobility. RESULTS The correlations between muscle force steadiness and mobility were not significant (P > .05) for either contraction type. However, MFA during ECC contractions only was correlated significantly with all measures of mobility-6 minute walk test (r = -0.48; P = .03), Timed Up and Go (r = 0.68; P = .01), stair ascent (r = 0.60; P = .01), and stair descent (r = 0.75; P < .01). CONCLUSION The identification of the relationship between ECC MFA and mobility in older adults who have fallen is novel. Although the correlations are not causal, these relationships suggest that inaccurate force output during ECC contractions of the knee extensors is linked to impaired mobility.
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Affiliation(s)
- Kaiwi Chung-Hoon
- University of Utah, Department of Physical Therapy, 520 Wakara Way, SLC, UT 84108
| | - Brian L. Tracy
- Colorado State University, Department of Health and Exercise Science, 220 Moby-B Complex, Fort Collins, CO 80523
| | - Leland E. Dibble
- University of Utah, Department of Physical Therapy, 520 Wakara Way, SLC, UT 84108
| | - Robin L. Marcus
- University of Utah, Department of Physical Therapy, 520 Wakara Way, SLC, UT 84108
| | - Paul Burgess
- University of Utah, Department of Physical Therapy, 520 Wakara Way, SLC, UT 84108
| | - Paul C. LaStayo
- University of Utah, Department of Physical Therapy, 520 Wakara Way, SLC, UT 84108
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Vila-Chã C, Falla D. Strength training, but not endurance training, reduces motor unit discharge rate variability. J Electromyogr Kinesiol 2015; 26:88-93. [PMID: 26586649 DOI: 10.1016/j.jelekin.2015.10.016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 09/29/2015] [Accepted: 10/27/2015] [Indexed: 11/25/2022] Open
Abstract
This study evaluates and compares the effects of strength and endurance training on motor unit discharge rate variability and force steadiness of knee extensor muscles. Thirty sedentary healthy men (age, 26.0±3.8yrs) were randomly assigned to strength training, endurance training or a control group. Conventional endurance and strength training was performed 3days per week, over a period of 6weeks. Maximum voluntary contraction (MVC), time to task failure (at 30% MVC), coefficient of variation (CoV) of force and of the discharges rates of motor units from the vastus medialis obliquus and vastus lateralis were determined as subjects performed 20% and 30% MVC knee extension contractions before and after training. CoV of motor unit discharges rates was significantly reduced for both muscles following strength training (P<0.001), but did not change in the endurance (P=0.875) or control group (P=0.995). CoV of force was reduced after the strength training intervention only (P<0.01). Strength training, but not endurance training, reduces motor unit discharge rate variability and enhances force steadiness of the knee extensors. These results provide new insights into the neuromuscular adaptations that occur with different training methods.
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Affiliation(s)
- Carolina Vila-Chã
- Polytechnic Institute of Guarda, Av. Dr. Francisco Sá Carneiro, n. 50, 6300-559, Portugal; Research Center in Sports Sciences, Health and Human Development (CIDESD), Quinta de Prados, 5001-801 Vila Real, Portugal.
| | - Deborah Falla
- Institute for Neurorehabilitation Systems, Bernstein Center for Computational Neuroscience, University Medical Center Göttingen, Georg-August University, Von-Siebold-Str. 6, Göttingen, Germany; Pain Clinic, Center for Anesthesiology, Emergency and Intensive Care Medicine, University Hospital Göttingen, Robert-Koch-Str. 40, Göttingen, Germany
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Saito A, Ando R, Akima H. Effects of prolonged patellar tendon vibration on force steadiness in quadriceps femoris during force-matching task. Exp Brain Res 2015; 234:209-17. [DOI: 10.1007/s00221-015-4447-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Accepted: 09/16/2015] [Indexed: 11/25/2022]
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Onushko T, Schmit BD, Hyngstrom A. The Effect of Antagonist Muscle Sensory Input on Force Regulation. PLoS One 2015; 10:e0133561. [PMID: 26186590 PMCID: PMC4506057 DOI: 10.1371/journal.pone.0133561] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 06/27/2015] [Indexed: 11/26/2022] Open
Abstract
The purpose of this study was to understand how stretch-related sensory feedback from an antagonist muscle affects agonist muscle output at different contraction levels in healthy adults. Ten young (25.3 ± 2.4 years), healthy subjects performed constant isometric knee flexion contractions (agonist) at 6 torque levels: 5%, 10%, 15%, 20%, 30%, and 40% of their maximal voluntary contraction. For half of the trials, subjects received patellar tendon taps (antagonist sensory feedback) during the contraction. We compared error in targeted knee flexion torque and hamstring muscle activity, with and without patellar tendon tapping, across the 6 torque levels. At lower torque levels (5%, 10%, and 15%), subjects produced greater knee torque error following tendon tapping compared with the same torque levels without tendon tapping. In contrast, we did not find any difference in torque output at higher target levels (20%, 30%, and 40%) between trials with and without tendon tapping. We also observed a load-dependent increase in the magnitude of agonist muscle activity after tendon taps, with no associated load-dependent increase in agonist and antagonist co-activation, or reflex inhibition from the antagonist tapping. The findings suggest that at relatively low muscle activity there is a deficiency in the ability to correct motor output after sensory disturbances, and cortical centers (versus sub-cortical) are likely involved.
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Affiliation(s)
- Tanya Onushko
- Department of Biomedical Engineering, Marquette University, Milwaukee, Wisconsin, United States of America
| | - Brian D. Schmit
- Department of Biomedical Engineering, Marquette University, Milwaukee, Wisconsin, United States of America
| | - Allison Hyngstrom
- Department of Physical Therapy, Marquette University, Milwaukee, Wisconsin, United States of America
- * E-mail:
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Krishnan C, Theuerkauf P. Effect of knee angle on quadriceps strength and activation after anterior cruciate ligament reconstruction. J Appl Physiol (1985) 2015; 119:223-31. [PMID: 25997949 DOI: 10.1152/japplphysiol.01044.2014] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 05/13/2015] [Indexed: 11/22/2022] Open
Abstract
Quadriceps strength and activation deficits after anterior cruciate ligament (ACL) injury or surgery are typically evaluated at joint positions that are biomechanically advantageous to the quadriceps muscle. However, the effect of knee joint position and the associated changes in muscle length on strength and activation is currently unknown in this population. Here, we examined the effect of knee angle on quadriceps strength, activation, and electrically evoked torque in individuals with ACL reconstruction. Furthermore, we evaluated whether knee angle mediated the relationship between quadriceps weakness and functional performance after ACL reconstruction. Knee strength and activation were tested bilaterally at 90° and 45° of knee flexion in 11 subjects with ACL reconstruction using an interpolated triplet technique. The magnitude of electrically evoked torque at rest was used to quantify peripheral muscle contractile property changes, and the single-leg hop for distance test was used to evaluate functional performance. The results indicated that although quadriceps strength deficits were similar between knee angles, voluntary activation deficits were significantly higher in the reconstructed leg at 45° of knee flexion. On the contrary, the side-to-side evoked torque at rest ratio [i.e., (reconstructed/nonreconstructed) × 100] was significantly lower at 90° than at 45° of knee flexion. The association between quadriceps strength and functional performance was stronger at 45° of knee flexion. The results provide novel evidence that quadriceps activation is selectively affected at 45° of knee flexion and emphasize the importance of assessing quadriceps strength and activation at this position when feasible because it better captures activation deficits.
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Affiliation(s)
- Chandramouli Krishnan
- Department of Physical Medicine and Rehabilitation, University of Michigan Medical School, Ann Arbor, Michigan; School of Kinesiology, University of Michigan, Ann Arbor, Michigan; and Deparment of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan
| | - Paul Theuerkauf
- Department of Physical Medicine and Rehabilitation, University of Michigan Medical School, Ann Arbor, Michigan
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Herda TJ, Cooper MA. Muscle-related differences in mechanomyography frequency–force relationships are model dependent. Med Biol Eng Comput 2015; 53:689-97. [DOI: 10.1007/s11517-015-1261-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Accepted: 02/27/2015] [Indexed: 10/23/2022]
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