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Gomez-Guerrero G, Avela J, Jussila I, Pihlajamäki E, Deng FY, Kidgell DJ, Ahtiainen JP, Walker S. Cortical and spinal responses to short-term strength training and detraining in young and older adults in rectus femoris muscle. Eur J Appl Physiol 2024; 124:2209-2223. [PMID: 38441691 PMCID: PMC11199260 DOI: 10.1007/s00421-024-05443-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Accepted: 02/14/2024] [Indexed: 06/27/2024]
Abstract
INTRODUCTION Strength training mitigates the age-related decline in strength and muscle activation but limited evidence exists on specific motor pathway adaptations. METHODS Eleven young (22-34 years) and ten older (66-80 years) adults underwent five testing sessions where lumbar-evoked potentials (LEPs) and motor-evoked potentials (MEPs) were measured during 20 and 60% of maximum voluntary contraction (MVC). Ten stimulations, randomly delivered, targeted 25% of maximum compound action potential for LEPs and 120, 140, and 160% of active motor threshold (aMT) for MEPs. The 7-week whole-body resistance training intervention included five exercises, e.g., knee extension (5 sets) and leg press (3 sets), performed twice weekly and was followed by 4 weeks of detraining. RESULTS Young had higher MVC (~ 63 N·m, p = 0.006), 1-RM (~ 50 kg, p = 0.002), and lower aMT (~ 9%, p = 0.030) than older adults at baseline. Young increased 1-RM (+ 18 kg, p < 0.001), skeletal muscle mass (SMM) (+ 0.9 kg, p = 0.009), and LEP amplitude (+ 0.174, p < 0.001) during 20% MVC. Older adults increased MVC (+ 13 N·m, p = 0.014), however, they experienced decreased LEP amplitude (- 0.241, p < 0.001) during 20% MVC and MEP amplitude reductions at 120% (- 0.157, p = 0.034), 140% (- 0.196, p = 0.026), and 160% (- 0.210, p = 0.006) aMT during 60% MVC trials. After detraining, young and older adults decreased 1-RM, while young adults decreased SMM. CONCLUSION Higher aMT and MEP amplitude in older adults were concomitant with lower baseline strength. Training increased strength in both groups, but divergent modifications in cortico-spinal activity occurred. Results suggest that the primary locus of adaptation occurs at the spinal level.
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Affiliation(s)
- Gonzalo Gomez-Guerrero
- Faculty of Sport and Health Sciences, NeuroMuscular Research Center, Viveca, VIV221, University of Jyväskylä, 40700, Jyväskylä, Finland.
| | - Janne Avela
- Faculty of Sport and Health Sciences, NeuroMuscular Research Center, Viveca, VIV221, University of Jyväskylä, 40700, Jyväskylä, Finland
| | - Ilkka Jussila
- Faculty of Sport and Health Sciences, NeuroMuscular Research Center, Viveca, VIV221, University of Jyväskylä, 40700, Jyväskylä, Finland
| | - Esa Pihlajamäki
- Faculty of Sport and Health Sciences, NeuroMuscular Research Center, Viveca, VIV221, University of Jyväskylä, 40700, Jyväskylä, Finland
| | - Fu-Yu Deng
- Faculty of Sport and Health Sciences, NeuroMuscular Research Center, Viveca, VIV221, University of Jyväskylä, 40700, Jyväskylä, Finland
| | - Dawson J Kidgell
- Monash Exercise Neuroplasticity Research Unit, School of Primary and Allied Health Care, Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, Australia
| | - Juha P Ahtiainen
- Faculty of Sport and Health Sciences, NeuroMuscular Research Center, Viveca, VIV221, University of Jyväskylä, 40700, Jyväskylä, Finland
| | - Simon Walker
- Faculty of Sport and Health Sciences, NeuroMuscular Research Center, Viveca, VIV221, University of Jyväskylä, 40700, Jyväskylä, Finland
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Lin CW, Jankaew A, Lin CF. Physical Therapy Intervention Effects on Alteration of Spinal Excitability in Patients With Chronic Ankle Instability: A Systematic Review and Meta-analysis. Sports Health 2024:19417381241253248. [PMID: 38804135 DOI: 10.1177/19417381241253248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2024] Open
Abstract
CONTEXT Chronic ankle instability (CAI) is a common injury in athletes. Different forms of physical therapy have been applied to the population with CAI to assess their impact on spinal excitability. OBJECTIVE The purpose of this systematic review and meta-analysis was to investigate the effectiveness of various physical therapy interventions on the alteration of spinal excitability in patients with CAI. DATA SOURCES Four databases (EMBASE, MEDLINE, Cochrane CENTRAL, and Scopus) were searched from inception to November 2022. STUDY SELECTION A total of 253 studies were obtained and screened; 11 studies on the effects of physical therapy intervention on the alteration of spinal excitability in patients with CAI were identified for meta-analysis. STUDY DESIGN Systematic review and meta-analysis. LEVEL OF EVIDENCE Level 3a. DATA EXTRACTION A total of 11 studies that included the maximal Hoffmann reflex normalized by the maximal muscle response (H/M ratio) in the peroneus longus and soleus muscles were extracted and summarized. The quality of the studies was assessed using the PEDro scale. RESULTS The extracted studies had an average PEDro score of 4.7 ± 1.4, indicating that most of them had fair-to-good quality. The physical therapy interventions included cryotherapy, taping, mobilization, proprioceptive training, and dry needling. The overall effects showed that the H/M ratios of the peroneus longus (P = 0.44, I2 = 0%) and soleus (P = 0.56,I2 = 22%) muscles were not changed by physical therapy in patients with CAI. CONCLUSION The meta-analysis indicated that physical therapy interventions such as cryotherapy, taping, mobilization, proprioceptive training, and dry needling do not alter the spinal excitability in patients with CAI. Given that only 1 study reported ineffective changes in spinal excitability with dry needling, more research is essential to establish and validate its efficacy. PROSPERO REGISTRATION CRD42022372998.
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Affiliation(s)
- Chia-Wei Lin
- Institute of Allied Health Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Amornthep Jankaew
- Department of Physical Therapy, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Cheng-Feng Lin
- Institute of Allied Health Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Department of Physical Therapy, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Physical Therapy Center, National Cheng Kung University Hospital, Tainan, Taiwan
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Gonçalves AD, Pezarat-Correia P, Vila-Chã C, Mendonça GV. Effects of Acute Sleep Deprivation on the Sequential Rate of Torque Development throughout the Force-Time Curve. Sleep Sci 2023; 16:e454-e461. [PMID: 38197028 PMCID: PMC10773507 DOI: 10.1055/s-0043-1776869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 03/27/2023] [Indexed: 01/11/2024] Open
Abstract
Objective The impact of sleep deprivation on the physiological determinants of explosive torque production remains poorly understood. We aimed at determining the acute effects of 24 hours of sleep deprivation on the sequential rate of torque development (RTD) obtained during plantar flexion through maximum voluntary isometric contraction (MVIC). Materials and Methods The study included 14 healthy-young adults (8 men and 6 women). The participants visited the laboratory on 2 different occasions: without and with 24 hours of sleep deprivation. In each session, the subjects were tested for RTD of the plantar flexors with concomitant recordings of the electromyographic (EMG) amplitude of the soleus over the following time intervals: 0 to 30, 30 to 50, 50 to 100, and 100 to 150 ms. Results Sleep deprivation did not affect peak RTD (without sleep deprivation: 283.3 ± 111.6 N.m.s -1 versus with sleep deprivation: 294.9 ± 99.2 N.m.s -1 ; p > 0.05) of plantar flexion. The sequential values of RTD, as well as the normalized amplitude of the soleus EMG, remained similar between both conditions (p > 0.05). Discussion In conclusion, we found that 24 hours of sleep deprivation do not affect muscle activation, nor explosive torque production throughout the torque-time curve. Thus, exercise performance and daily functionality in tasks involving rapid torque development might remain well preserved after 24 hours of acute sleep deprivation.
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Affiliation(s)
- André Dias Gonçalves
- Neuromuscular Research Lab, CIPER, Faculdade de Motricidade Humana, Universidade de Lisboa, Cruz Quebrada, Dafundo, Portugal
| | - Pedro Pezarat-Correia
- Neuromuscular Research Lab, CIPER, Faculdade de Motricidade Humana, Universidade de Lisboa, Cruz Quebrada, Dafundo, Portugal
| | - Carolina Vila-Chã
- CIDESD, Escola Superior de Educação, Comunicação e Desporto, Instituto Politécnico da Guarda, Guarda Portugal
| | - Gonçalo Vilhena Mendonça
- Neuromuscular Research Lab, CIPER, Faculdade de Motricidade Humana, Universidade de Lisboa, Cruz Quebrada, Dafundo, Portugal
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Nevanperä S, Hu N, Walker S, Avela J, Piirainen JM. Modulation of H-reflex and V-wave responses during dynamic balance perturbations. Exp Brain Res 2023; 241:1599-1610. [PMID: 37142781 DOI: 10.1007/s00221-023-06625-6] [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: 10/04/2022] [Accepted: 04/25/2023] [Indexed: 05/06/2023]
Abstract
Motoneuron excitability is possible to measure using H-reflex and V-wave responses. However, it is not known how the motor control is organized, how the H-reflex and V-wave responses modulate and how repeatable these are during dynamic balance perturbations. To assess the repeatability, 16 participants (8 men, 8 women) went through two, identical measurement sessions with ~ 48 h intervals, where maximal isometric plantar flexion (IMVC) and dynamic balance perturbations in horizontal, anterior-posterior direction were performed. Soleus muscle (SOL) neural modulation during balance perturbations were measured at 40, 70, 100 and 130 ms after ankle movement by using both H-reflex and V-wave methods. V-wave, which depicts the magnitude of efferent motoneuronal output (Bergmann et al. in JAMA 8:e77705, 2013), was significantly enhanced as early as 70 ms after the ankle movement. Both the ratio of M-wave-normalized V-wave (0.022-0.076, p < 0.001) and H-reflex (0.386-0.523, p < 0.001) increased significantly at the latency of 70 ms compared to the latency of 40 ms and remained at these levels at latter latencies. In addition, M-wave normalized V-wave/H-reflex ratio increased from 0.056 to 0.179 (p < 0.001). The repeatability of V-wave demonstrated moderate-to-substantial repeatability (ICC = 0.774-0.912) whereas the H-reflex was more variable showing fair-to-substantial repeatability (ICC = 0.581-0.855). As a conclusion, V-wave was enhanced already at 70 ms after the perturbation, which may indicate that increased activation of motoneurons occurred due to changes in descending drive. Since this is a short time-period for voluntary activity, some other, potentially subcortical responses might be involved for V-wave increment rather than voluntary drive. Our results addressed the usability and repeatability of V-wave method during dynamic conditions, which can be utilized in future studies.
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Affiliation(s)
- Samuli Nevanperä
- Sports Technology Program, Faculty of Sport and Health Sciences, University of Jyväskylä, Kidekuja 2, 88610, Vuokatti, Finland.
- NeuroMuscular Research Center, Faculty of Sport and Health Sciences, University of Jyväskylä, Rautpohjankatu 8, PL35, 40700, Jyväskylä, Finland.
| | - Nijia Hu
- NeuroMuscular Research Center, Faculty of Sport and Health Sciences, University of Jyväskylä, Rautpohjankatu 8, PL35, 40700, Jyväskylä, Finland
| | - Simon Walker
- NeuroMuscular Research Center, Faculty of Sport and Health Sciences, University of Jyväskylä, Rautpohjankatu 8, PL35, 40700, Jyväskylä, Finland
| | - Janne Avela
- NeuroMuscular Research Center, Faculty of Sport and Health Sciences, University of Jyväskylä, Rautpohjankatu 8, PL35, 40700, Jyväskylä, Finland
| | - Jarmo M Piirainen
- Sports Technology Program, Faculty of Sport and Health Sciences, University of Jyväskylä, Kidekuja 2, 88610, Vuokatti, Finland
- NeuroMuscular Research Center, Faculty of Sport and Health Sciences, University of Jyväskylä, Rautpohjankatu 8, PL35, 40700, Jyväskylä, Finland
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Theodosiadou A, Henry M, Duchateau J, Baudry S. Revisiting the use of Hoffmann reflex in motor control research on humans. Eur J Appl Physiol 2023; 123:695-710. [PMID: 36571622 DOI: 10.1007/s00421-022-05119-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 12/17/2022] [Indexed: 12/27/2022]
Abstract
Research in movement science aims at unravelling mechanisms and designing methods for restoring and maximizing human functional capacity, and many techniques provide access to neural adjustments (acute changes) or long-term adaptations (chronic changes) underlying changes in movement capabilities. First described by Paul Hoffmann over a century ago, when an electrical stimulus is applied to a peripheral nerve, this causes action potentials in afferent axons, primarily the Ia afferents of the muscle spindles, which recruit homonymous motor neurons, thereby causing an electromyographic response known as the Hoffmann (H) reflex. This technique is a valuable tool in the study of the neuromuscular function in humans and has provided relevant information in the neural control of movement. The large use of the H reflex in motor control research on humans relies in part to its relative simplicity. However, such simplicity masks subtleties that require rigorous experimental protocols and careful data interpretation. After highlighting basic properties and methodological aspects that should be considered for the correct use of the H-reflex technique, this brief narrative review discusses the purpose of the H reflex and emphasizes its use as a tool to assess the effectiveness of Ia afferents in discharging motor neurones. The review also aims to reconsider the link between H-reflex modulation and Ia presynaptic inhibition, the use of the H-reflex technique in motor control studies, and the effects of ageing. These aspects are summarized as recommendations for the use of the H reflex in motor control research on humans.
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Affiliation(s)
- Anastasia Theodosiadou
- Laboratory of Applied Biology, Research Unit in Applied Neurophysiology (LABNeuro), Faculty of Motor Sciences, ULB-Neurosciences Institute (UNI), Université Libre de Bruxelles (ULB), 808 Route de Lennik, CP 640, 1070, Brussels, Belgium
| | - Mélanie Henry
- Laboratory of Applied Biology, Research Unit in Applied Neurophysiology (LABNeuro), Faculty of Motor Sciences, ULB-Neurosciences Institute (UNI), Université Libre de Bruxelles (ULB), 808 Route de Lennik, CP 640, 1070, Brussels, Belgium
| | - Jacques Duchateau
- Laboratory of Applied Biology, Research Unit in Applied Neurophysiology (LABNeuro), Faculty of Motor Sciences, ULB-Neurosciences Institute (UNI), Université Libre de Bruxelles (ULB), 808 Route de Lennik, CP 640, 1070, Brussels, Belgium
| | - Stéphane Baudry
- Laboratory of Applied Biology, Research Unit in Applied Neurophysiology (LABNeuro), Faculty of Motor Sciences, ULB-Neurosciences Institute (UNI), Université Libre de Bruxelles (ULB), 808 Route de Lennik, CP 640, 1070, Brussels, Belgium.
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Kushnir A, Fedchyshyn B, Kachmar O. Review of effects of spinal manipulative therapy on neurological symptoms. J Bodyw Mov Ther 2023; 34:66-73. [PMID: 37301560 DOI: 10.1016/j.jbmt.2023.04.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 11/21/2022] [Accepted: 04/11/2023] [Indexed: 06/12/2023]
Abstract
BACKGROUND Neurological disorders are the leading cause of disability in the world. Neurological symptoms significantly affect the well-being of the individual. Spinal manipulative therapy (SMT) is a complementary method often used for people with neurological disorders. OBJECTIVE This study aimed to review the existing literature on the effects of SMT on common clinical symptoms of neurologic disorders and the quality of life. METHODS Narrative review was conducted through the literature published between January 2000 and April 2020 in English. The search was performed across four databases: PubMed, Google Scholar, PEDro, and Index to Chiropractic Literature. We used combinations of keywords related to SMT, neurological symptoms, and quality of life. Studies on both symptomatic and asymptomatic populations of different ages were included. RESULTS 35 articles were selected. Evidence for the administration of SMT for neurological symptoms is insufficient and sparse. Most studies focused on the effects of SMT on pain, revealing its benefits for spinal pain. SMT may increase strength in asymptomatic people and populations with spinal pain and stroke. SMT was reported to affect spasticity, muscle stiffness, motor function, autonomic function, and balance problems, but these studies were limited in number to make conclusions. An important finding was the positive influence of SMT on the quality of life in people with spinal pain, balance impairments, and cerebral palsy. CONCLUSION SMT may be beneficial for the symptomatic treatment of neurological disorders. SMT can positively affect the quality of life. However, limited evidence is available, and further high-quality research is required.
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Affiliation(s)
- A Kushnir
- Elita Rehabilitation Center, Kozyavkin Medical Group, Ukraine
| | - B Fedchyshyn
- Elita Rehabilitation Center, Kozyavkin Medical Group, Ukraine
| | - O Kachmar
- Elita Rehabilitation Center, Kozyavkin Medical Group, Ukraine.
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Jeon S, Sontag SA, Herda TJ, Trevino MA. Chronic training status affects muscle excitation of the vastus lateralis during repeated contractions. SPORTS MEDICINE AND HEALTH SCIENCE 2023; 5:42-49. [PMID: 36994174 PMCID: PMC10040376 DOI: 10.1016/j.smhs.2022.12.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 11/23/2022] [Accepted: 12/31/2022] [Indexed: 01/03/2023] Open
Abstract
This study examined electromyographic amplitude (EMGRMS)-force relationships during repeated submaximal knee extensor muscle actions among chronic aerobically-(AT), resistance-trained (RT), and sedentary (SED) individuals. Fifteen adults (5/group) attempted 20 isometric trapezoidal muscle actions at 50% of maximal strength. Surface electromyography (EMG) was recorded from vastus lateralis (VL) during the muscle actions. For the first and last successfully completed contractions, linear regression models were fit to the log-transformed EMGRMS-force relationships during the linearly increasing and decreasing segments, and the b terms (slope) and a terms (antilog of y-intercept) were calculated. EMGRMS was averaged during steady force. Only the AT completed all 20 muscle actions. During the first contraction, the b terms for RT (1.301 ± 0.197) were greater than AT (0.910 ± 0.123; p = 0.008) and SED (0.912 ± 0.162; p = 0.008) during the linearly increasing segment, and in comparison to the linearly decreasing segment (1.018 ± 0.139; p = 0.014), respectively. For the last contraction, the b terms for RT were greater than AT during the linearly increasing (RT = 1.373 ± 0.353; AT = 0.883 ± 0.129; p = 0.018) and decreasing (RT = 1.526 ± 0.328; AT = 0.970 ± 0.223; p = 0.010) segments. In addition, the b terms for SED increased from the linearly increasing (0.968 ± 0.144) to decreasing segment (1.268 ± 0.126; p = 0.015). There were no training, segment, or contraction differences for the a terms. EMGRMS during steady force increased from the first- ([64.08 ± 51.68] μV) to last-contraction ([86.73 ± 49.55] μV; p = 0.001) collapsed across training statuses. The b terms differentiated the rate of change for EMGRMS with increments in force among training groups, indicating greater muscle excitation to the motoneuron pool was necessary for the RT than AT during the linearly increasing and decreasing segments of a repetitive task.
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Tøien T, Unhjem R, Berg OK, Aagaard P, Wang E. Strength versus endurance trained master athletes: Contrasting neurophysiological adaptations. Exp Gerontol 2023; 171:112038. [PMID: 36442699 DOI: 10.1016/j.exger.2022.112038] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 11/11/2022] [Accepted: 11/21/2022] [Indexed: 11/27/2022]
Abstract
Neural factors play a critical role in the age-related decline in maximal strength and rate of force development (RFD). However, it is uncertain how the age-related attenuation in neuromuscular function may be mitigated in strength or endurance trained master athletes. In this study we applied evoked spinal motoneuron recordings to examine descending motor drive, i.e., efferent drive from supraspinal and spinal centres during maximal voluntary contraction (MVC; V-wave) and H-reflex excitability measured at 10 % MVC in older (>65 yrs) and younger (<35 yrs) strength athletes (n = 21), endurance athletes (n = 17) and untrained control participants (n = 30). Both strength (b = 0.09 [0.01-0.18], p = 0.038) and endurance training (b = 0.14 [0.04-0.23], p = 0.006) were associated with a high V-wave amplitude. This was likely explained by an elevated H-reflex excitability (b = 0.23 [0.11-0.35], p < 0.001) in endurance trained participants, which failed to be seen in strength trained participants. These contrasting neurophysiological properties were accompanied by different physiological traits; strength training was associated with high maximal strength (b = 107.5 [84.6 to 130.4] kg, p < 0.001) and RFD (b = 3171 [2248 to 4094] N‧s-1, p < 0.001), whereas endurance training was associated with elevated maximal oxygen uptake (V̇O2max; b = 13.6 [8.0-19.2] ml‧kg-1‧min-1, p < 0.001). This pattern was apparent irrespective of age, although all traits were negatively associated with advanced age (p < 0.05). In conclusion, strength trained individuals demonstrate higher descending motor drive (elevated V-wave responses), compared to age-matched untrained individuals. Endurance trained individuals also showed elevated V-wave responses, uniquely accompanied by enhanced α-motoneuron excitability and/or reduced pre/postsynaptic inhibition (elevated H-reflex responses). Since a high descending motor drive is a key component of strong muscle contractions, strength training should be emphasized to sustain the ability to carry out force-dependent tasks at older age.
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Affiliation(s)
- Tiril Tøien
- Department of Health and Social Sciences, Molde University College, Norway.
| | - Runar Unhjem
- Faculty of Education and Arts, Nord University, Bodø, Norway
| | - Ole Kristian Berg
- Department of Health and Social Sciences, Molde University College, Norway
| | - Per Aagaard
- Department of Sports Science and Clinical Biomechanics, Research Unit for Muscle Physiology and Biomechanics, University of Southern Denmark, Odense, Denmark
| | - Eivind Wang
- Department of Health and Social Sciences, Molde University College, Norway; Department of Østmarka, Division of Mental Health Care, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway
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Batista-Ferreira L, Rabelo NF, da Cruz GM, Costa JNDA, Elias LA, Mezzarane RA. Effects of voluntary contraction on the soleus H-reflex of different amplitudes in healthy young adults and in the elderly. Front Hum Neurosci 2022; 16:1039242. [PMID: 36590063 PMCID: PMC9797586 DOI: 10.3389/fnhum.2022.1039242] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 11/30/2022] [Indexed: 12/23/2022] Open
Abstract
A number of H-reflex studies used a moderate steady voluntary contraction in an attempt to keep the motoneuron pool excitability relatively constant. However, it is not clear whether the voluntary muscle activation itself represents a confounding factor for the elderly, as a few ongoing mechanisms of reflex modulation might be compromised. Further, it is well-known that the amount of either inhibition or facilitation from a given conditioning depends on the size of the test H-reflex. The present study aimed at evaluating the effects of voluntary contraction over a wide range of reflex amplitudes. A significant reflex facilitation during an isometric voluntary contraction of the soleus muscle (15% of the maximal voluntary isometric contraction-MVC) was found for both young adults and the elderly (p < 0.05), regardless of their test reflex amplitudes (considering the ascending limb of the H-reflex recruitment curve-RC). No significant difference was detected in the level of reflex facilitation between groups for all the amplitude parameters extracted from the RC. Simulations with a computational model of the motoneuron pool driven by stationary descending commands yielded qualitatively similar amount of reflex facilitation, as compared to human experiments. Both the experimental and modeling results suggest that possible age-related differences in spinal cord mechanisms do not significantly influence the reflex modulation during a moderate voluntary muscle activation. Therefore, a background voluntary contraction of the ankle extensors (e.g., similar to the one necessary to maintain upright stance) can be used in experiments designed to compare the RCs of both populations. Finally, in an attempt to elucidate the controversy around changes in the direct motor response (M-wave) during contraction, the maximum M-wave (Mmax) was compared between groups and conditions. It was found that the Mmax significantly increases (p < 0.05) during contraction and decreases (p < 0.05) with age arguably due to muscle fiber shortening and motoneuron loss, respectively.
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Affiliation(s)
- Leandra Batista-Ferreira
- Laboratory of Signal Processing and Motor Control, Faculty of Physical Education, University of Brasília, Brasília, Goiás, Brazil
| | - Natielle Ferreira Rabelo
- Neural Engineering Research Laboratory, Center for Biomedical Engineering, University of Campinas, Campinas, São Paulo, Brazil,Department of Electronics and Biomedical Engineering, School of Electrical and Computer Engineering, University of Campinas, Campinas, São Paulo, Brazil
| | - Gabriel Menezes da Cruz
- Laboratory of Signal Processing and Motor Control, Faculty of Physical Education, University of Brasília, Brasília, Goiás, Brazil
| | | | - Leonardo Abdala Elias
- Neural Engineering Research Laboratory, Center for Biomedical Engineering, University of Campinas, Campinas, São Paulo, Brazil,Department of Electronics and Biomedical Engineering, School of Electrical and Computer Engineering, University of Campinas, Campinas, São Paulo, Brazil
| | - Rinaldo André Mezzarane
- Laboratory of Signal Processing and Motor Control, Faculty of Physical Education, University of Brasília, Brasília, Goiás, Brazil,Postgraduate Program in Biomedical Engineering, University of Brasília, Brasília, Goiás, Brazil,*Correspondence: Rinaldo André Mezzarane,
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Balinski M, Madhavan S. "Magic" Number of Treadmill Sessions Needed to Achieve Meaningful Change in Gait Speed After Stroke: A Systematic Review. Am J Phys Med Rehabil 2022; 101:826-835. [PMID: 34799509 PMCID: PMC9108112 DOI: 10.1097/phm.0000000000001920] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
ABSTRACT The purpose of this systematic review was to determine the number of treadmill training sessions needed to make a meaningful change in gait speed for chronic stroke survivors. Relevant databases were searched up through February 2020. Articles were included if they fit the following criteria: stroke onset more than 5 mos, intention to treat with traditional treadmill training, and gait speed included as an outcome. Change in gait speed after intervention was used to classify treadmill groups as responders (at least 0.1 m/sec change) or nonresponders (less than 0.1 m/sec change). Seventeen articles met our criteria, resulting in a total of 19 intervention groups. Ten groups were classified as responders and completed a mean of 30.5 sessions within 6 wks, whereas nonresponders completed 20.4 sessions within 10 wks, indicating that at least 30 treadmill sessions (preferably in a period of 10 wks and at least 40 mins per session) is necessary to reach a meaningful change in gait speed. Although these trends were noted between the responder and nonresponder groups, no firm conclusions can be drawn regarding the "magic" number of sessions chronic stroke survivors should perform given the low correlation between number of sessions and change in gait speed.
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Affiliation(s)
- Mariah Balinski
- Brain Plasticity Lab, Department of Physical Therapy, College of Applied Health Sciences, University of Illinois at Chicago, Chicago, IL, USA
- Graduate Program in Rehabilitation Science, College of Applied Health Sciences, University of Illinois, Chicago, IL, USA
| | - Sangeetha Madhavan
- Brain Plasticity Lab, Department of Physical Therapy, College of Applied Health Sciences, University of Illinois at Chicago, Chicago, IL, USA
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Marathamuthu S, Selvanayagam VS, Yusof A. Contralateral Effects of Eccentric Exercise and DOMS of the Plantar Flexors: Evidence of Central Involvement. RESEARCH QUARTERLY FOR EXERCISE AND SPORT 2022; 93:240-249. [PMID: 32976088 DOI: 10.1080/02701367.2020.1819526] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 08/28/2020] [Indexed: 06/11/2023]
Abstract
Purpose: Peripheral and central factors play important roles in the reduction of motor performance following damaging eccentric exercise and delayed onset muscle soreness (DOMS). Following this regime, contralateral limbs could also be affected; however, the factors involved remain inconclusive. The purpose of this study was to distinguish the peripheral and central factors following eccentric contraction and DOMS of the plantar flexors in treated and contralateral homologous limbs. Methods: Ten males (BMI = 25.08 ± 1.69kgm-2; age = 28.70 ± 4.24 years) were randomly assigned to experimental (DOM) or control (CON) groups. The DOM group performed a damaging eccentric exercise, while the CON group rested. Plasma creatine kinase (CK), pain rating scale (PRS), muscle stiffness, maximal voluntary contraction (MVC), and neural voluntary activation (VA) were measured before, after 10 min, and after 24, 48, and 72 hr on treated and contralateral limbs. Results: Following exercise, CK increased until after 48 hr, while PRS increased until after 72 hr compared to the CON group. Importantly, MVC was reduced at all time points, with the greatest reduction observed after 24 hr (-16%), while VA was affected until after 48 hr, with the greatest reduction at after 10 min (-7%). Interestingly, a "cross-over effect" was observed in contralateral limbs when PRS, MVC, and VA were negatively affected following the same pattern (time line) as treated limbs (-13% peak MVC reduction; -3.5% peak VA reduction). Conclusion: These findings suggest a substantial central contribution to the reduction in force immediately following eccentric exercise and to a lesser extent during the latter part of DOMS in both treated and contralateral limbs.
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Navid MS, Niazi IK, Lelic D, Amjad I, Kumari N, Shafique M, Holt K, Rashid U, Drewes AM, Haavik H. Chiropractic Spinal Adjustment Increases the Cortical Drive to the Lower Limb Muscle in Chronic Stroke Patients. Front Neurol 2022; 12:747261. [PMID: 35185747 PMCID: PMC8854235 DOI: 10.3389/fneur.2021.747261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 12/31/2021] [Indexed: 11/13/2022] Open
Abstract
This study aimed to investigate the effects of a single session of chiropractic spinal adjustment on the cortical drive to the lower limb in chronic stroke patients. In a single-blinded, randomized controlled parallel design study, 29 individuals with chronic stroke and motor weakness in a lower limb were randomly divided to receive either chiropractic spinal adjustment or a passive movement control intervention. Before and immediately after the intervention, transcranial magnetic stimulation (TMS)-induced motor evoked potentials (MEPs) were recorded from the tibialis anterior (TA) muscle of the lower limb with the greatest degree of motor weakness. Differences in the averaged peak-peak MEP amplitude following interventions were calculated using a linear regression model. Chiropractic spinal adjustment elicited significantly larger MEP amplitude (pre = 0.24 ± 0.17 mV, post = 0.39 ± 0.23 mV, absolute difference = +0.15 mV, relative difference = +92%, p < 0.001) compared to the control intervention (pre = 0.15 ± 0.09 mV, post = 0.16 ± 0.09 mV). The results indicate that chiropractic spinal adjustment increases the corticomotor excitability of ankle dorsiflexor muscles in people with chronic stroke. Further research is required to investigate whether chiropractic spinal adjustment increases dorsiflexor muscle strength and walking function in people with stroke.
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Affiliation(s)
- Muhammad Samran Navid
- Mech-Sense, Department of Gastroenterology and Hepatology, Aalborg University Hospital, Aalborg, Denmark
- Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
- Centre for Chiropractic Research, New Zealand College of Chiropractic, Auckland, New Zealand
| | - Imran Khan Niazi
- Centre for Chiropractic Research, New Zealand College of Chiropractic, Auckland, New Zealand
- Faculty of Health and Environmental Sciences, Health and Rehabilitation Research Institute, AUT University, Auckland, New Zealand
- Department of Health Science and Technology, Centre for Sensory-Motor Interactions, Aalborg University, Aalborg, Denmark
- *Correspondence: Imran Khan Niazi
| | - Dina Lelic
- Mech-Sense, Department of Gastroenterology and Hepatology, Aalborg University Hospital, Aalborg, Denmark
| | - Imran Amjad
- Faculty of Rehabilitation and Allied Health Sciences, Riphah International University, Islamabad, Pakistan
- Faculty of Engineering and Applied Sciences, Riphah International University, Islamabad, Pakistan
| | - Nitika Kumari
- Centre for Chiropractic Research, New Zealand College of Chiropractic, Auckland, New Zealand
- Faculty of Health and Environmental Sciences, Health and Rehabilitation Research Institute, AUT University, Auckland, New Zealand
| | - Muhammad Shafique
- Faculty of Rehabilitation and Allied Health Sciences, Riphah International University, Islamabad, Pakistan
| | - Kelly Holt
- Centre for Chiropractic Research, New Zealand College of Chiropractic, Auckland, New Zealand
| | - Usman Rashid
- Faculty of Health and Environmental Sciences, Health and Rehabilitation Research Institute, AUT University, Auckland, New Zealand
| | - Asbjørn Mohr Drewes
- Mech-Sense, Department of Gastroenterology and Hepatology, Aalborg University Hospital, Aalborg, Denmark
- Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
| | - Heidi Haavik
- Centre for Chiropractic Research, New Zealand College of Chiropractic, Auckland, New Zealand
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13
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Bertschinger R, Giboin LS, Gruber M. Endurance Trained Athletes Do Not per se Have Higher Hoffmann Reflexes Than Recreationally Active Controls. Front Physiol 2021; 12:736067. [PMID: 34867445 PMCID: PMC8633408 DOI: 10.3389/fphys.2021.736067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Accepted: 10/21/2021] [Indexed: 11/13/2022] Open
Abstract
The impact of endurance training on spinal neural circuitries remains largely unknown. Some studies have reported higher H-reflexes in endurance trained athletes and therefore, adaptations within the Ia afferent pathways after long term endurance training have been suggested. In the present study we tested the hypothesis that cyclists (n = 12) demonstrate higher Hoffmann reflexes (H-reflexes) compared to recreationally active controls (n = 10). Notwithstanding, highly significant differences in endurance performance (VO2peak: 60.6 for cyclists vs. 46.3 ml/min/kg for controls (p < 0.001) there was no difference in the size of the SOL H-reflex between cyclists and controls (Hmax/Mmax ratio 61.3 vs. 60.0%, respectively (p = 0.840). Further analyses of the H and M recruitment curves for SOL revealed a significant steeper slope of the M recruitment curve in the group of cyclists (76.2 ± 3.8° vs. 72.0 ± 4.4°, p = 0.046) without a difference in the H-recruitment curve (84.6 ± 3.0° vs. 85.0 ± 2.8°, p = 0.784) compared to the control group. Cycling is classified as an endurance sport and thus the findings of the present study do not further support the assumption that long-term aerobic training leads to a general increase of the H-reflex. Amongst methodological differences in assessing the H-reflex, the training-specific sensorimotor control of the endurance sport itself might differently affect the responsiveness of spinal motoneurons on Ia-afferent inputs.
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Affiliation(s)
- Raphael Bertschinger
- Human Performance Research Centre, Department of Sport Science, University of Konstanz, Konstanz, Germany
| | - Louis-Solal Giboin
- Human Performance Research Centre, Department of Sport Science, University of Konstanz, Konstanz, Germany
| | - Markus Gruber
- Human Performance Research Centre, Department of Sport Science, University of Konstanz, Konstanz, Germany
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14
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Del Vecchio A, Casolo A, Dideriksen JL, Aagaard P, Felici F, Falla D, Farina D. Lack of increased rate of force development after strength training is explained by specific neural, not muscular, motor unit adaptations. J Appl Physiol (1985) 2021; 132:84-94. [PMID: 34792405 DOI: 10.1152/japplphysiol.00218.2021] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
While maximal force increases following short-term isometric strength training, the rate of force development (RFD) may remain relatively unaffected. The underlying neural and muscular mechanisms during rapid contractions after strength training are largely unknown. Since strength training increases the neural drive to muscles, it may be hypothesized that there are distinct neural or muscular adaptations determining the change in RFD independently of an increase in maximal force. Therefore, we examined motor unit population data acquired from surface electromyography during the rapid generation of force before and after four weeks of strength training. We observed that strength training did not change the RFD because it did not influence the number of motor units recruited per second or their initial discharge rate during rapid contractions. While strength training did not change motoneuron behaviour in the force increase phase of rapid contractions, it increased the discharge rate of motoneurons (by ~4 spikes/s) when reaching the plateau phase (~150 ms) of the rapid contractions, determining an increase in maximal force production. Computer simulations with a motor unit model that included neural and muscular properties, closely matched the experimental observations and demonstrated that the lack of change in RFD following training is primarily mediated by an unchanged maximal recruitment speed of motoneurons. These results demonstrate that maximal force and contraction speed are determined by different adaptations in motoneuron behaviour following strength training and indicate that increases in the recruitment speed of motoneurons are required to evoke training-induced increases in RFD.
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Affiliation(s)
- Alessandro Del Vecchio
- Department of Artificial Intelligence in Biomedical Engineering, Friedrich-Alexander University, Erlangen, Bavaria, Germany
| | - Andrea Casolo
- Department of Biomedical Sciences, University of Padua, Padua, Italy
| | | | - Per Aagaard
- Department of Sports Science and Clinical Biomechanics, Muscle Physiology and Biomechanics Research Unit, University of Southern Denmark, Odense, Denmark
| | - Francesco Felici
- Department of Movement, Human and Health Sciences, University of Rome "Foro Italico", Rome, Italy
| | - Deborah Falla
- Centre of Precision Rehabilitation for Spinal Pain (CPR Spine), School of Sport, Exercise and Rehabilitation Sciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Dario Farina
- Department of Bioengineering, Imperial College London, London, United Kingdom
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15
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Tøien T, Haglo H, Nyberg SK, Rao SV, Stunes AK, Mosti MP, Wang E. Maximal strength training-induced increase in efferent neural drive is not reflected in relative protein expression of SERCA. Eur J Appl Physiol 2021; 121:3421-3430. [PMID: 34498135 PMCID: PMC8571128 DOI: 10.1007/s00421-021-04807-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 09/01/2021] [Indexed: 10/26/2022]
Abstract
INTRODUCTION Maximal strength training (MST), performed with heavy loads (~ 90% of one repetition maximum; 1RM) and few repetitions, yields large improvements in efferent neural drive, skeletal muscle force production, and skeletal muscle efficiency. However, it is elusive whether neural adaptations following such high intensity strength training may be accompanied by alterations in energy-demanding muscular factors. METHODS Sixteen healthy young males (24 ± 4 years) were randomized to MST 3 times per week for 8 weeks (n = 8), or a control group (CG; n = 8). Measurements included 1RM and rate of force development (RFD), and evoked potentials recordings (V-wave and H-reflex normalized to M-wave (M) in the soleus muscle) applied to assess efferent neural drive to maximally contracting skeletal muscle. Biopsies were obtained from vastus lateralis and analyzed by western blots and real-time PCR to investigate the relative protein expression and mRNA expression of Sarcoplasmic Reticulum Ca2+ ATPase (SERCA) 1 and SERCA2. RESULTS Significant improvements in 1RM (17 ± 9%; p < 0.001) and early (0-100 ms), late (0-200 ms) and maximal RFD (31-53%; p < 0.01) were observed after MST, accompanied by increased maximal Vmax/Msup-ratio (9 ± 14%; p = 0.046), with no change in H-reflex to M-wave ratio. No changes were observed in the CG. No pre- to post-training differences were found in mRNA or protein expressions of SERCA1 and SERCA2 in either group. CONCLUSION MST increased efferent neural drive to maximally contracting skeletal muscle, causing improved force production. No change was observed in SERCA expression, indicating that responses to high intensity strength training may predominantly be governed by neural adaptations.
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Affiliation(s)
- Tiril Tøien
- Department of Health and Social Sciences, Molde University College, Britvegen 2, 6410, Molde, Norway.
| | - Håvard Haglo
- Department of Health and Social Sciences, Molde University College, Britvegen 2, 6410, Molde, Norway.,Myworkout, Medical Rehabilitation Clinic, Trondheim, Norway
| | - Stian Kwak Nyberg
- Department of Circulation and Medical Imaging, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway
| | - Shalini Vasudev Rao
- Cambridge Institute, University of Cambridge, Cambridge, UK.,Department of Clinical and Molecular Medicine, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway
| | - Astrid Kamilla Stunes
- Department of Clinical and Molecular Medicine, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway.,Medical Clinic, St. Olavs University Hospital, Trondheim, Norway
| | - Mats Peder Mosti
- Department of Clinical and Molecular Medicine, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway.,Medical Clinic, St. Olavs University Hospital, Trondheim, Norway
| | - Eivind Wang
- Department of Health and Social Sciences, Molde University College, Britvegen 2, 6410, Molde, Norway.,Department of Medicine, University of Utah, Salt Lake City, UT, USA.,Department of Østmarka, Division of Mental Health Care, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway
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16
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Marshall PW, Finn HT, Enoka RM. Declines in muscle contractility and activation during isometric contractions of the knee extensors vary with contraction intensity and exercise volume. Exp Physiol 2021; 106:2096-2106. [PMID: 34411379 DOI: 10.1113/ep089788] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 08/16/2021] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? Is there a critical threshold beyond which the loss of muscle contractility is regulated by the level of muscle activation during single-limb exercise of differing intensities and volumes? What is the main finding and its importance? Plateaus in the decline in muscle contractility during single-limb knee extension depended on both exercise volume and contraction intensity. A plateau was only evident with an increase in exercise volume. Muscle activation increased and did not decline despite substantial reductions in contractility. The findings indicate that the decrease in muscle contractility exhibited by resistance-trained men during the performance of submaximal isometric contractions with the knee extensors was not regulated by the level of muscle activation. ABSTRACT Our study examined the influence of contraction intensity and exercise volume on changes in muscle contractility and activation of the knee extensor muscles. Maximal voluntary torque (MVT) and rate of change in torque, surface electromyograms, voluntary activation, V-waves and quadriceps resting twitch measures were assessed in 10 resistance-trained men during two experimental sessions. Each session began with an initial baseline series of contractions at a fixed intensity of 40% or 80% MVT. The 40%-only session continued with five contractions to task failure at 40% MVT. The 80% session continued with five contractions to failure each at 80%, 60% and 40% MVT. Greater reductions in MVT were observed during the baseline contractions of the 40%-only session compared with the 80% session at each matched-volume time point (P < 0.05), with similar changes in twitch values (P < 0.001). MVT and twitch values plateaued at each intensity during the 80% session and were significantly different across intensities: 80% > 60% > 40% (P < 0.001). There were no differences for measures during the five contractions at 40% MVT performed on the different days, despite a greater volume of exercise performed prior to the 40% MVT during the 80% session. At each contraction intensity, a plateau in contractility loss was observed as more contractions were performed. We found that initial increases in muscle activation were maintained in the presence of increases in exercise volume and, in contrast to the critical-threshold hypothesis, did not decline in parallel with reductions in muscle contractility.
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Affiliation(s)
- Paul W Marshall
- Department of Exercise Sciences, University of Auckland, Auckland, New Zealand.,Human Performance Laboratory, School of Health Sciences, Western Sydney University, Sydney, Australia
| | - Harrison T Finn
- Neuroscience Research Australia (NeuRA), Sydney, Australia.,University of New South Wales, Sydney, Australia
| | - Roger M Enoka
- Department of Integrative Physiology, University of Colorado, Boulder, CO, USA
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17
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Marshall PW, Melville GW, Cross R, Marquez J, Harrison I, Enoka RM. Fatigue, pain, and the recovery of neuromuscular function after consecutive days of full-body resistance exercise in trained men. Eur J Appl Physiol 2021; 121:3103-3116. [PMID: 34350481 DOI: 10.1007/s00421-021-04777-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 07/25/2021] [Indexed: 11/28/2022]
Abstract
PURPOSE This study measured the self-reported level of fatigue, pain, and neuromuscular function of the knee extensor muscles over a three-day period that included two consecutive days of full-body resistance exercises. METHODS 10 resistance-trained men performed two consecutive days of full-body resistance exercise. Muscle activation (electromyography and voluntary activation), contractility, and presynaptic inhibition of Ia afferents (homosynaptic and GABA mediated presynaptic inhibition) for the quadriceps were examined from femoral and posterior tibial nerve stimulation. RESULTS Fatigue and pain were elevated after Day 1, and were not reduced to pre-exercise levels at the start of Day 2 (p < 0.05). Maximal voluntary torque (- 51.4 Nm, 95% CI = 12.4-90.4 Nm, p = 0.005) and rate of torque development (- 469 Nm.s-1, 95% CI = 109-829 Nm.s-1, p = 0.006) were reduced after Day 1, had recovered by Day 2, and did not change after the second training session. The maximal amplitude and rate of rise for the quadriceps twitch were reduced after both training sessions (p < 0.01), with recovery 24 h each session. The maximal amplitude and rate of early muscle activation were reduced after Day 1 (p < 0.01), but no changes were observed for voluntary activation, H-reflex size and shape, or measures of Ia presynaptic inhibition. CONCLUSION Resistance exercise in the presence of elevated fatigue and pain from a previous training session does not worsen recovery, or lead to significant alterations in quadriceps neuromuscular function. Reduction in muscle contractility, in the absence of declines in muscle activation, does not lead to decreased voluntary torque.
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Affiliation(s)
- Paul W Marshall
- Human Performance Laboratory, School of Health Science, Western Sydney University, Penrith, Australia. .,Department of Exercise Science, University of Auckland, Building 907, Newmarket, Auckland, 1023, New Zealand.
| | - Geoffrey W Melville
- Faculty of Science, Medicine, and Health, University of Wollongong, Wollongong, Australia
| | - Rebecca Cross
- Human Performance Laboratory, School of Health Science, Western Sydney University, Penrith, Australia
| | - John Marquez
- Human Performance Laboratory, School of Health Science, Western Sydney University, Penrith, Australia
| | - Isaac Harrison
- Human Performance Laboratory, School of Health Science, Western Sydney University, Penrith, Australia
| | - Roger M Enoka
- Department of Integrative Physiology, University of Colorado, Boulder, CO, USA
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18
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Neuromuscular Adaptations after an Altitude Training Camp in Elite Judo Athletes. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18136777. [PMID: 34202491 PMCID: PMC8296934 DOI: 10.3390/ijerph18136777] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Revised: 06/18/2021] [Accepted: 06/20/2021] [Indexed: 11/17/2022]
Abstract
The aim of this study was to investigate neuromuscular adaptations in elite judo athletes after three weeks of power-oriented strength training at terrestrial altitude (2320 m). Nineteen men were assigned to altitude training (AL) (22.1 ± 2.3 years) and sea level training (SL) (22.6 ± 4.1 years). Neuromuscular assessment consisted of: (1) maximal isometric knee extensor (KE) torque, (2) KE rate of torque development (RTD), (3) quadriceps activity and voluntary activation, (4) soleus H-reflex, (5) quadriceps single (TTW) and double twitch torque (TDB100) and contraction time (CTTW). There were no significant differences between groups at baseline for any of the observed parameters. Significant differences were found between groups in terms of change in RTD (p = 0.04). Cohen’s d showed a positive significant effect (0.43) in the SL group and a negative significant effect (−0.58) in the AL group. The difference between groups in changes in CTTW as a function of altitude was on the edge of significance (p = 0.077). CTTW increased by 8.1 ± 9.0% in the AL group (p = 0.036) and remained statistically unchanged in the SL group. Only the AL group showed a relationship between changes in TTW and TDB100 and changes in RTD at posttest (p = 0.022 and p = 0.016, respectively). Altitude induced differences in muscular adaptations likely due to greater peripheral fatigue.
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The contemporary model of vertebral column joint dysfunction and impact of high-velocity, low-amplitude controlled vertebral thrusts on neuromuscular function. Eur J Appl Physiol 2021; 121:2675-2720. [PMID: 34164712 PMCID: PMC8416873 DOI: 10.1007/s00421-021-04727-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 05/20/2021] [Indexed: 02/08/2023]
Abstract
Purpose There is growing evidence that vertebral column function and dysfunction play a vital role in neuromuscular control. This invited review summarises the evidence about how vertebral column dysfunction, known as a central segmental motor control (CSMC) problem, alters neuromuscular function and how spinal adjustments (high-velocity, low-amplitude or HVLA thrusts directed at a CSMC problem) and spinal manipulation (HVLA thrusts directed at segments of the vertebral column that may not have clinical indicators of a CSMC problem) alters neuromuscular function.
Methods The current review elucidates the peripheral mechanisms by which CSMC problems, the spinal adjustment or spinal manipulation alter the afferent input from the paravertebral tissues. It summarises the contemporary model that provides a biologically plausible explanation for CSMC problems, the manipulable spinal lesion. This review also summarises the contemporary, biologically plausible understanding about how spinal adjustments enable more efficient production of muscular force. The evidence showing how spinal dysfunction, spinal manipulation and spinal adjustments alter central multimodal integration and motor control centres will be covered in a second invited review. Results Many studies have shown spinal adjustments increase voluntary force and prevent fatigue, which mainly occurs due to altered supraspinal excitability and multimodal integration. The literature suggests physical injury, pain, inflammation, and acute or chronic physiological or psychological stress can alter the vertebral column’s central neural motor control, leading to a CSMC problem. The many gaps in the literature have been identified, along with suggestions for future studies. Conclusion Spinal adjustments of CSMC problems impact motor control in a variety of ways. These include increasing muscle force and preventing fatigue. These changes in neuromuscular function most likely occur due to changes in supraspinal excitability. The current contemporary model of the CSMC problem, and our understanding of the mechanisms of spinal adjustments, provide a biologically plausible explanation for how the vertebral column’s central neural motor control can dysfunction, can lead to a self-perpetuating central segmental motor control problem, and how HVLA spinal adjustments can improve neuromuscular function.
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20
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Mendonca GV, Vila-Chã C, Teodósio C, Goncalves AD, Freitas SR, Mil-Homens P, Pezarat-Correia P. Contralateral training effects of low-intensity blood-flow restricted and high-intensity unilateral resistance training. Eur J Appl Physiol 2021; 121:2305-2321. [PMID: 33982187 DOI: 10.1007/s00421-021-04708-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 04/30/2021] [Indexed: 10/21/2022]
Abstract
PURPOSE Determine whether unilateral low-intensity blood-flow restricted (LIBFR) exercise is as effective as high-intensity (HI) resistance training for improving contralateral muscle strength. METHODS Thirty healthy adults (20-30 years) were randomly allocated to the following dynamic plantar-flexion training interventions: HI [75% of one-repetition maximum (1RM), 4 sets, 10 reps] and LIBFR [20% of 1RM, 4 sets, 30 + 15 + 15 + 15 reps]. Evoked V-wave and H-reflex recruitment curves, as well as maximal voluntary contraction (MVC) and panoramic ultrasound assessments of the trained and untrained soleus muscles were obtained pre-training, post-4 weeks of training and post-4 weeks of detraining. RESULTS Both interventions failed to increase contralateral MVC and muscle cross-sectional area (CSA). Yet, contralateral rate of torque development (RTD) was enhanced by both regimens (12-26%) and this was accompanied by heightened soleus EMG within the first milliseconds of the rising torque-time curve (14-22%; p < 0.05). These improvements were dissipated after detraining. Contralateral adaptations were not accompanied by changes in V-wave or H-reflex excitability. Conversely, LIBFR and HI elicited a similar magnitude of ipsilateral increase in MVC, RTD and CSA post-training (10-18%). Improvements in V-wave amplitude and soleus EMG were limited to the trained leg assigned to LIBFR training (p < 0.05). While gains in strength and CSA remained preserved post-4 weeks of detraining, this did not occur with RTD. CONCLUSION Since gains in RTD were similar between interventions, our findings indicate that both training regimens can be used interchangeably for improving contralateral rapid torque production. Ultimately, this may be beneficial in circumstances of limb immobilization after injury or surgery.
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Affiliation(s)
- Goncalo V Mendonca
- Neuromuscular Research Lab, Faculdade de Motricidade Humana, Universidade de Lisboa, Estrada da Costa, Cruz Quebrada, Dafundo, 1499-002, Lisbon, Portugal. .,CIPER, Faculdade de Motricidade Humana, Universidade de Lisboa, Estrada da Costa, Cruz Quebrada, 1499-002, Dafundo, Portugal.
| | - Carolina Vila-Chã
- Polytechnic Institute of Guarda, Av. Dr. Francisco Sá Carneiro, n. 50, 6300-559, Guarda, Portugal.,Research Center in Sports Sciences, Health and Human Development (CIDESD), Vila-Real, Portugal
| | - Carolina Teodósio
- Neuromuscular Research Lab, Faculdade de Motricidade Humana, Universidade de Lisboa, Estrada da Costa, Cruz Quebrada, Dafundo, 1499-002, Lisbon, Portugal
| | - André D Goncalves
- Neuromuscular Research Lab, Faculdade de Motricidade Humana, Universidade de Lisboa, Estrada da Costa, Cruz Quebrada, Dafundo, 1499-002, Lisbon, Portugal
| | - Sandro R Freitas
- Neuromuscular Research Lab, Faculdade de Motricidade Humana, Universidade de Lisboa, Estrada da Costa, Cruz Quebrada, Dafundo, 1499-002, Lisbon, Portugal.,CIPER, Faculdade de Motricidade Humana, Universidade de Lisboa, Estrada da Costa, Cruz Quebrada, 1499-002, Dafundo, Portugal
| | - Pedro Mil-Homens
- Neuromuscular Research Lab, Faculdade de Motricidade Humana, Universidade de Lisboa, Estrada da Costa, Cruz Quebrada, Dafundo, 1499-002, Lisbon, Portugal.,CIPER, Faculdade de Motricidade Humana, Universidade de Lisboa, Estrada da Costa, Cruz Quebrada, 1499-002, Dafundo, Portugal
| | - Pedro Pezarat-Correia
- Neuromuscular Research Lab, Faculdade de Motricidade Humana, Universidade de Lisboa, Estrada da Costa, Cruz Quebrada, Dafundo, 1499-002, Lisbon, Portugal.,CIPER, Faculdade de Motricidade Humana, Universidade de Lisboa, Estrada da Costa, Cruz Quebrada, 1499-002, Dafundo, Portugal
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21
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Espeit L, Brownstein CG, Royer N, Besson T, Martin V, Millet GY, Lapole T. Central fatigue aetiology in prolonged trail running races. Exp Physiol 2021; 106:663-672. [DOI: 10.1113/ep089177] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 01/05/2021] [Indexed: 01/15/2023]
Affiliation(s)
- Loic Espeit
- Univ Lyon UJM‐Saint‐Etienne Inter‐university Laboratory of Human Movement Biology EA 7424 Saint‐Etienne F‐42023 France
| | - Callum G Brownstein
- Univ Lyon UJM‐Saint‐Etienne Inter‐university Laboratory of Human Movement Biology EA 7424 Saint‐Etienne F‐42023 France
| | - Nicolas Royer
- Univ Lyon UJM‐Saint‐Etienne Inter‐university Laboratory of Human Movement Biology EA 7424 Saint‐Etienne F‐42023 France
| | - Thibault Besson
- Univ Lyon UJM‐Saint‐Etienne Inter‐university Laboratory of Human Movement Biology EA 7424 Saint‐Etienne F‐42023 France
| | - Vincent Martin
- Clermont‐Auvergne University AME2P Clermont‐Ferrand 63000 France
- Institut Universitaire de France (IUF) France
| | - Guillaume Y Millet
- Univ Lyon UJM‐Saint‐Etienne Inter‐university Laboratory of Human Movement Biology EA 7424 Saint‐Etienne F‐42023 France
- Institut Universitaire de France (IUF) France
| | - Thomas Lapole
- Univ Lyon UJM‐Saint‐Etienne Inter‐university Laboratory of Human Movement Biology EA 7424 Saint‐Etienne F‐42023 France
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22
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Tallent J, Woodhead A, Frazer AK, Hill J, Kidgell DJ, Howatson G. Corticospinal and spinal adaptations to motor skill and resistance training: Potential mechanisms and implications for motor rehabilitation and athletic development. Eur J Appl Physiol 2021; 121:707-719. [PMID: 33389142 DOI: 10.1007/s00421-020-04584-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Accepted: 12/12/2020] [Indexed: 12/12/2022]
Abstract
Optimal strategies for enhancing strength and improving motor skills are vital in athletic performance and clinical rehabilitation. Initial increases in strength and the acquisition of new motor skills have long been attributed to neurological adaptations. However, early increases in strength may be predominantly due to improvements in inter-muscular coordination rather than the force-generating capacity of the muscle. Despite the plethora of research investigating neurological adaptations from motor skill or resistance training in isolation, little effort has been made in consolidating this research to compare motor skill and resistance training adaptations. The findings of this review demonstrated that motor skill and resistance training adaptations show similar short-term mechanisms of adaptations, particularly at a cortical level. Increases in corticospinal excitability and a release in short-interval cortical inhibition occur as a result of the commencement of both resistance and motor skill training. Spinal changes show evidence of task-specific adaptations from the acquired motor skill, with an increase or decrease in spinal reflex excitability, dependant on the motor task. An increase in synaptic efficacy of the reticulospinal projections is likely to be a prominent mechanism for driving strength adaptations at the subcortical level, though more research is needed. Transcranial electric stimulation has been shown to increase corticospinal excitability and augment motor skill adaptations, but limited evidence exists for further enhancing strength adaptations from resistance training. Despite the logistical challenges, future work should compare the longitudinal adaptations between motor skill and resistance training to further optimise exercise programming.
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Affiliation(s)
- Jamie Tallent
- Faculty of Sport, Health and Applied Sciences, St Mary's University, Waldgrave Road, Twickenham, TW1 4SX, UK.
| | - Alex Woodhead
- Faculty of Sport, Health and Applied Sciences, St Mary's University, Waldgrave Road, Twickenham, TW1 4SX, UK
| | - Ashlyn K Frazer
- Department of Physiotherapy, School of Primary and Allied Health Care, Faculty of Medicine, Nursing and Health Science, Monash University, Melbourne, Australia
| | - Jessica Hill
- Faculty of Sport, Health and Applied Sciences, St Mary's University, Waldgrave Road, Twickenham, TW1 4SX, UK
| | - Dawson J Kidgell
- Department of Physiotherapy, School of Primary and Allied Health Care, Faculty of Medicine, Nursing and Health Science, Monash University, Melbourne, Australia
| | - Glyn Howatson
- Department of Sport, Exercise and Rehabilitation, Northumbria University, Newcastle-upon-Tyne, UK.,Water Research Group, Faculty of Natural and Agricultural Sciences, North West University, Potchefstroom, South Africa
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23
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Hortobágyi T, Granacher U, Fernandez-Del-Olmo M, Howatson G, Manca A, Deriu F, Taube W, Gruber M, Márquez G, Lundbye-Jensen J, Colomer-Poveda D. Functional relevance of resistance training-induced neuroplasticity in health and disease. Neurosci Biobehav Rev 2020; 122:79-91. [PMID: 33383071 DOI: 10.1016/j.neubiorev.2020.12.019] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 12/18/2020] [Accepted: 12/19/2020] [Indexed: 01/13/2023]
Abstract
Repetitive, monotonic, and effortful voluntary muscle contractions performed for just a few weeks, i.e., resistance training, can substantially increase maximal voluntary force in the practiced task and can also increase gross motor performance. The increase in motor performance is often accompanied by neuroplastic adaptations in the central nervous system. While historical data assigned functional relevance to such adaptations induced by resistance training, this claim has not yet been systematically and critically examined in the context of motor performance across the lifespan in health and disease. A review of muscle activation, brain and peripheral nerve stimulation, and imaging data revealed that increases in motor performance and neuroplasticity tend to be uncoupled, making a mechanistic link between neuroplasticity and motor performance inconclusive. We recommend new approaches, including causal mediation analytical and hypothesis-driven models to substantiate the functional relevance of resistance training-induced neuroplasticity in the improvements of gross motor function across the lifespan in health and disease.
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Affiliation(s)
- Tibor Hortobágyi
- Center for Human Movement Sciences, University of Groningen, University Medical CenterGroningen, Groningen, Netherlands.
| | - Urs Granacher
- Division of Training and Movement Sciences, Research Focus Cognition Sciences, University of Potsdam, Potsdam, Germany
| | - Miguel Fernandez-Del-Olmo
- Area of Sport Sciences, Faculty of Sports Sciences and Physical Education, Center for Sport Studies, King Juan Carlos University, Madrid, Spain
| | - Glyn Howatson
- Department of Sport, Exercise and Rehabilitation, Northumbria University, Newcastle, UK; Water Research Group, North West University, Potchefstroom, South Africa
| | - Andrea Manca
- Department of Biomedical Sciences, University of Sassari, Sassari, Italy
| | - Franca Deriu
- Department of Biomedical Sciences, University of Sassari, Sassari, Italy
| | - Wolfgang Taube
- Department of Neurosciences and Movement Sciences, University of Fribourg, Fribourg, Switzerland
| | - Markus Gruber
- Human Performance Research Centre, Department of Sport Science, University of Konstanz, Konstanz, Germany
| | - Gonzalo Márquez
- Department of Physical Education and Sport, Faculty of Sports Sciences and Physical Education, University of A Coruña, A Coruña, Spain
| | - Jesper Lundbye-Jensen
- Movement & Neuroscience, Department of Nutrition, Exercise & Sports Department of Neuroscience, University of Copenhagenk, Faculty of Health Science, Universidad Isabel I, Burgos, Spain
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24
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Niazi IK, Kamavuako EN, Holt K, Janjua TAM, Kumari N, Amjad I, Haavik H. The Effect of Spinal Manipulation on the Electrophysiological and Metabolic Properties of the Tibialis Anterior Muscle. Healthcare (Basel) 2020; 8:healthcare8040548. [PMID: 33321904 PMCID: PMC7764559 DOI: 10.3390/healthcare8040548] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 12/07/2020] [Accepted: 12/07/2020] [Indexed: 12/31/2022] Open
Abstract
There is growing evidence showing that spinal manipulation increases muscle strength in healthy individuals as well as in people with some musculoskeletal and neurological disorders. However, the underlying mechanism by which spinal manipulation changes muscle strength is less clear. This study aimed to assess the effects of a single spinal manipulation session on the electrophysiological and metabolic properties of the tibialis anterior (TA) muscle. Maximum voluntary contractions (MVC) of the ankle dorsiflexors, high-density electromyography (HDsEMG), intramuscular EMG, and near-infrared spectroscopy (NIRS) were recorded from the TA muscle in 25 participants with low level recurring spinal dysfunction using a randomized controlled crossover design. The following outcomes: motor unit discharge rate (MUDR), strength (force at MVC), muscle conduction velocity (CV), relative changes in oxy- and deoxyhemoglobin were assessed pre and post a spinal manipulation intervention and passive movement control. Repeated measures ANOVA was used to assess within and between-group differences. Following the spinal manipulation intervention, there was a significant increase in MVC (p = 0.02; avg 18.87 ± 28.35%) and a significant increase in CV in both the isometric steady-state (10% of MVC) contractions (p < 0.01; avg 22.11 ± 11.69%) and during the isometric ramp (10% of MVC) contractions (p < 0.01; avg 4.52 ± 4.58%) compared to the control intervention. There were no other significant findings. The observed TA strength and CV increase, without changes in MUDR, suggests that the strength changes observed following spinal manipulation are, in part, due to increased recruitment of larger, higher threshold motor units. Further research needs to investigate the longer term and potential functional effects of spinal manipulation in various patients who may benefit from improved muscle function and greater motor unit recruitment.
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Affiliation(s)
- Imran Khan Niazi
- Centre for Chiropractic Research, New Zealand College of Chiropractic, Auckland 1060, New Zealand; (K.H.); (N.K.); (I.A.)
- Faculty of Health & Environmental Sciences, Health & Rehabilitation Research Institute, AUT University, Auckland 0627, New Zealand
- Department of Health Science and Technology, Aalborg University, Aalborg 9220, Denmark;
- Correspondence: (I.K.N.); (H.H.)
| | - Ernest Nlandu Kamavuako
- Department of Informatics, King’s College London, London WC2R 2LS, UK;
- Faculté de Médecine, Université de Kindu, Kindu, Congo
| | - Kelly Holt
- Centre for Chiropractic Research, New Zealand College of Chiropractic, Auckland 1060, New Zealand; (K.H.); (N.K.); (I.A.)
| | | | - Nitika Kumari
- Centre for Chiropractic Research, New Zealand College of Chiropractic, Auckland 1060, New Zealand; (K.H.); (N.K.); (I.A.)
- Faculty of Health & Environmental Sciences, Health & Rehabilitation Research Institute, AUT University, Auckland 0627, New Zealand
| | - Imran Amjad
- Centre for Chiropractic Research, New Zealand College of Chiropractic, Auckland 1060, New Zealand; (K.H.); (N.K.); (I.A.)
- Faculty of Rehabilitation and Allied Sciences, Riphah International University, Islamabad 46000, Pakistan
| | - Heidi Haavik
- Centre for Chiropractic Research, New Zealand College of Chiropractic, Auckland 1060, New Zealand; (K.H.); (N.K.); (I.A.)
- Correspondence: (I.K.N.); (H.H.)
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25
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Magalhães IEJ, Burgo VC, Neto RB, Mezzarane RA. Changes in the input-output relation of the Hoffmann reflex recruitment curve after submaximal fatiguing contraction of the antagonist muscles. Somatosens Mot Res 2020; 38:54-59. [PMID: 33169647 DOI: 10.1080/08990220.2020.1845135] [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] [Indexed: 10/23/2022]
Abstract
PURPOSE The central nervous system adapts strategies to compensate the decreased motor capacities of a fatigued muscle. However, data on neurophysiological adaptations of muscles other than those under fatigue are scarce. The present study was designed to evaluate the effects of submaximal fatiguing contraction (leading to a task failure) induced in ankle dorsiflexors muscles on the excitability of the Hoffmann reflex (H-reflex) of an ankle plantarflexor (soleus muscle). MATERIALS AND METHODS Twenty-three physically active males (75.5 ± 8.3 kg; 1.77 ± 0.08 m; 27.0 ± 8.0 years) were asked to maintain the contraction level of the right ankle dorsiflexors at 60% of the maximal isometric voluntary contraction (MIVC). Task failure was defined when the force level dropped below 40% MIVC for 5 consecutive seconds. The input-output relation of the ascending limb of the recruitment curve of the soleus H-reflex was examined at 0 min, 5 min, 10 min, 15 min and 20 min after the task failure. RESULTS The amplitude parameter representing the first recruited motoneurons (threshold H-reflex - H@th) was significantly higher at 5 min, 10 min, 15 min and 20 min after task failure as compared to control (Hth) (p < 0.05). On the other hand, the parameter that represents the activation of the relatively higher threshold motoneurons (H@100) was reduced (as compared to control - H100), but only at 20 min after the task failure (p < 0.05). CONCLUSIONS These results suggest differential reflex modulation of the soleus H-reflex after fatigue of the ankle dorsiflexors, that probably reflects neuronal adaptations underlying motor control around the ankle joint.
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Affiliation(s)
- Igor E J Magalhães
- Laboratory of Signal Processing and Motor Control, Universidade de Brasília-UnB, Brasília, Brazil
| | - Vinícius C Burgo
- Laboratory of Signal Processing and Motor Control, Universidade de Brasília-UnB, Brasília, Brazil
| | - Roque B Neto
- Laboratory of Signal Processing and Motor Control, Universidade de Brasília-UnB, Brasília, Brazil
| | - Rinaldo A Mezzarane
- Laboratory of Signal Processing and Motor Control, Universidade de Brasília-UnB, Brasília, Brazil
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26
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Mendonca GV, Pezarat-Correia P, Gonçalves AD, Gomes M, Correia JM, Vila-Chã C. Sex differences in soleus muscle H-reflex and V-wave excitability. Exp Physiol 2020; 105:1928-1938. [PMID: 32886814 DOI: 10.1113/ep088820] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 09/02/2020] [Indexed: 12/12/2022]
Abstract
NEW FINDINGS What is the central question of this study? How do H-reflex and V-wave excitability compare between men and women engaging in similar levels of physical activity? What is the main finding and its importance? H-reflex excitability is lower in women than in men because of their greater level of antagonist co-activation during sustained plantar flexion isometric exercise. In addition, supraspinal drive is similar between men and women independently of their differences in H-reflex excitability and antagonist muscle co-activation. ABSTRACT We compared H-reflex and V-wave excitability between men and women engaging in similar levels of physical activity. We also explored whether differences in antagonist muscle co-activation between sexes might partially explain sexual dimorphism in the excitability of the H-reflex and V-wave. Fifty-seven young participants were included (29 men: 21.7 ± 2.3 years; 28 women: 22.4 ± 3.3 years). Soleus M- and H-recruitment curves were constructed on a tonic background muscle activation. V-waves were elicited during maximal voluntary contraction (MVC). Besides being stronger than women, men achieved greater Hmax /Mmax values and presented a steeper slope of the ascending limb of the H-reflex recruitment curve (P < 0.05). The current intensity required to elicit Hmax was lower for men (P < 0.05). The co-activation of the tibialis anterior muscle during the sustained plantar flexions was greater in women (ratio between tibialis and soleus normalized EMG: 20.5 vs. 8.3%, P < 0.05). Covariance analysis showed that sexual dimorphism in H-reflex excitability was dissipated when controlling for antagonist co-activation. V-wave normalized amplitude was similar between sexes even after controlling for the effects of Hmax /Mmax and antagonist co-activation as covariates. Thus, women exhibit lower H-reflex excitability than men and this is dependent on their higher level of antagonist muscle co-activation. While sex differences in antagonist co-activation persist during MVCs, this is not the case for V-wave normalized amplitude. Thus, although the efficacy of the transmission between Ia afferent fibres to α-motoneurons is lower in women because of a greater level of antagonist co-activation, our findings are consistent with similar supraspinal drive between sexes.
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Affiliation(s)
- Goncalo V Mendonca
- Neuromuscular Research Lab, Faculdade de Motricidade Humana, Universidade de Lisboa, Lisbon, Portugal.,CIPER, Faculdade de Motricidade Humana, Universidade de Lisboa, Lisbon, Portugal
| | - Pedro Pezarat-Correia
- Neuromuscular Research Lab, Faculdade de Motricidade Humana, Universidade de Lisboa, Lisbon, Portugal.,CIPER, Faculdade de Motricidade Humana, Universidade de Lisboa, Lisbon, Portugal
| | - André D Gonçalves
- Neuromuscular Research Lab, Faculdade de Motricidade Humana, Universidade de Lisboa, Lisbon, Portugal
| | - Miguel Gomes
- Neuromuscular Research Lab, Faculdade de Motricidade Humana, Universidade de Lisboa, Lisbon, Portugal
| | - Joana M Correia
- Neuromuscular Research Lab, Faculdade de Motricidade Humana, Universidade de Lisboa, Lisbon, Portugal.,CIPER, Faculdade de Motricidade Humana, Universidade de Lisboa, Lisbon, Portugal
| | - Carolina Vila-Chã
- Polytechnic Institute of Guarda, Guarda, Portugal.,Health and Human Development (CIDESD), Research Center in Sports Sciences, Vila Real, Portugal
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27
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Zhai SS, Wen DT, Liu TY, Hou WQ. A warm-up performed with proper-weight sandbags on the leg improves the speed and RPE performance of 100 m sprint in collegiate male sprinters. J Sports Med Phys Fitness 2020; 61:10-17. [PMID: 32878421 DOI: 10.23736/s0022-4707.20.10639-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Muscle performance can be notably improved following a preloading maximal or near maximal stimulus due to the induction of postactivation potentiation, but the success of a preloading exercise in generating a postactivation potentiation response depends on the balance between fatigue and potentiation. However, the optimal warm-up strategy for sprint runners before a match may be not well established until now. METHODS Fifteen well-trained male sprint runners performed four different warm-up protocols: warm-up with 0% body mass; warm-up with 2% body mass; warm-up with 4% body mass; warm-up with 8% body mass. The weight-bearing sandbag was tied about 3~5 cm above each ankle joint. During the 100-meter test, the time and rating of perceived exertion (RPE) in the first 30 meters, time in the first 60 meters, and time in the 100 meters were recorded, respectively. Two-high-speed digital video cameras were separately set in the sagittal planes on the left side of a line drawn at a distance of 30 m and 60 m from the start line to record the sprint motion. RESULTS A warm-up performed with a sandbag weighted 4% of body mass could significantly improve the time and the RPE score of 100 m sprint by improving average velocity, stride frequency, average stride length, and average accelerated velocity during the sections of 0~30 m, 30~60 m and 60~100 m. This positive effect was better than that of 2% body-weigh effect. However, a warm-up performed with a sandbag weighted 8% of body mass had no significant influence on the performance of a 100 m sprint. CONCLUSIONS Current results indicated that a warm-up performed with proper-weight(4% body mass) sandbags on the leg was beneficial to the improvement of 100 m sprint performance, and the mechanism might be that it effectively activated the main muscles and neuromuscular regulation of running and produced a better postactivation potentiation.
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28
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Helgerud J, Thomsen SN, Hoff J, Strandbråten A, Leivseth G, Unhjem R, Wang E. Maximal strength training in patients with Parkinson's disease: impact on efferent neural drive, force-generating capacity, and functional performance. J Appl Physiol (1985) 2020; 129:683-690. [PMID: 32790593 DOI: 10.1152/japplphysiol.00208.2020] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Parkinson's disease (PD) is characterized by progressive neurological deterioration, typically accompanied by reductions in skeletal muscle force-generating capacity (FGC) and functional performance. Physical activity has the potential to counteract this debilitating outcome, however, it is elusive if high-intensity strength training included in conventional treatment may improve results. Therefore, we randomly assigned 22 PD patients (74 ± 9 yr) to conventional rehabilitation with or without maximal strength training (MST) performed as leg press and chest press at ~90% of one repetition maximum (1RM), five times per week for 4 wk. FGC, physical performance, and efferent neural drive assessed as evoked potentials (V-wave normalized to M-wave in m. soleus) were measured following training. Results revealed that only MST improved 1RM leg press (101 ± 23 to 118 ± 18 kg) and chest press (36 ± 15 to 41 ± 15 kg), plantar flexion maximal voluntary contraction (235 ± 125 to 293 ± 158 N·m), and rate of force development (373 ± 345 to 495 ± 446 N·m·s-1; all P < 0.05; different from controls P < 0.05). FGC improvements were accompanied by an increased efferent neural drive to maximally contracting musculature (V-to-M ratio: 0.17 ± 0.12 to 0.24 ± 0.15; P < 0.05; different from controls P < 0.05), improved physical performance (stair climbing: 21.0 ± 9.2 to 14.4 ± 5.2 s; timed up and go: 7.8 ± 3.3 to 6.2 ± 2.5 s; both P < 0.05), and self-perceived improvement in health (3.1 ± 0.5 to 2.6 ± 0.9) and social activities functioning (2.2 ± 1.0 to 1.5 ± 1.1; both P < 0.05). No changes were observed in the control group. In conclusion, this study shows that MST improves FGC, neuromuscular function, and functional performance and advocates that high-intensity strength training should be implemented as an adjunct therapy in the treatment of PD patients.NEW & NOTEWORTHY This randomized, controlled trial documents that supervised high-intensity strength training improves efferent neural drive, maximal muscle strength, rate of force development, and functional performance in patients with Parkinson's disease (PD). In contrast, no differences were observed in these outcome variables in patients receiving conventional treatment consisting of recreational physical activity with low-to-medium intensity. Consequently, this study advocates that high-intensity strength training should be implemented in the clinical treatment of PD patients.
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Affiliation(s)
- J Helgerud
- Department of Circulation and Medical Imaging, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway.,Myworkout, Medical Rehabilitation Clinic, Trondheim, Norway
| | - S N Thomsen
- Centre for Physical Activity Research, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - J Hoff
- Myworkout, Medical Rehabilitation Clinic, Trondheim, Norway.,Department of Physical Medicine and Rehabilitation, St. Olavs University Hospital, Trondheim, Norway
| | - A Strandbråten
- Hokksund Medical Rehabilitation Center, Hokksund, Norway
| | - G Leivseth
- Department of Clinical Medicine, Arctic University of Norway, Tromsø, Norway
| | - R Unhjem
- Faculty of Nursing and Health Sciences, Nord University, Bodø, Norway
| | - E Wang
- Department of Circulation and Medical Imaging, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway.,Faculty of Health Sciences and Social Care, Molde University College, Molde, Norway.,Department of Internal Medicine, University of Utah, Salt Lake City, Utah.,Department of Rehabilitation, Rīga Stradiņš University, Riga, Latvia
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29
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Aagaard P, Bojsen-Møller J, Lundbye-Jensen J. Assessment of Neuroplasticity With Strength Training. Exerc Sport Sci Rev 2020; 48:151-162. [DOI: 10.1249/jes.0000000000000229] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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30
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D Gonçalves A, Teodosio C, Pezarat-Correia P, Vila-Chã C, V Mendonca G. Effects of acute sleep deprivation on H reflex and V wave. J Sleep Res 2020; 30:e13118. [PMID: 32567138 DOI: 10.1111/jsr.13118] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 05/12/2020] [Accepted: 05/18/2020] [Indexed: 12/01/2022]
Abstract
The impact of sleep deprivation on muscular strength and power remains poorly understood. We aimed to determine the acute effects of 24 hr of sleep deprivation on H-reflex and V-wave excitability. Fourteen healthy young adults (eight men, six women) were included. Participants visited the laboratory on two different occasions, without and with 24 hr of sleep deprivation. In each session, participants were tested for maximal voluntary contraction (MVC) of the plantar flexors and dorsiflexors, soleus H- and M-recruitment curves, and evoked V wave, as well as tibialis anterior/soleus electromyographic co-activation. Twenty-four hours of sleep deprivation did not affect either plantarflexion MVC or soleus electromyographic normalized amplitude (p > .05). Moreover, H-reflex and V-wave peak-to-peak normalized amplitude did not change with sleep deprivation (p > .05). Conversely, we obtained a significant increase in antagonist/agonist level of co-activation during MVC post-sleep deprivation (6.2 ± 5.2%, p < .01). In conclusion, we found that H-reflex and V-wave responses are well preserved after 24 hr of sleep deprivation, revealing that descending neural drive and/or modulation in Ia afferent input remains largely unaffected under these circumstances. Yet, sleep deprivation affects motor control by exacerbating the magnitude of antagonist/agonist co-activation during forceful muscle contractions and this is novel.
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Affiliation(s)
- André D Gonçalves
- Neuromuscular Research Laboratory, Faculdade de Motricidade Humana, Universidade de Lisboa, Dafundo, Portugal
| | - Carolina Teodosio
- Neuromuscular Research Laboratory, Faculdade de Motricidade Humana, Universidade de Lisboa, Dafundo, Portugal
| | - Pedro Pezarat-Correia
- Neuromuscular Research Laboratory, Faculdade de Motricidade Humana, Universidade de Lisboa, Dafundo, Portugal.,CIPER, Faculdade de Motricidade Humana, Universidade de Lisboa, Dafundo, Portugal
| | - Carolina Vila-Chã
- Polytechnic Institute of Guarda, Guarda, Portugal.,Research Center in Sports Sciences, Health and Human Development (CIDESD), Vila-Real, Portugal
| | - Goncalo V Mendonca
- Neuromuscular Research Laboratory, Faculdade de Motricidade Humana, Universidade de Lisboa, Dafundo, Portugal.,CIPER, Faculdade de Motricidade Humana, Universidade de Lisboa, Dafundo, Portugal
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31
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Walker S, Piitulainen H, Manlangit T, Avela J, Baker SN. Older adults show elevated intermuscular coherence in eyes‐open standing but only young adults increase coherence in response to closing the eyes. Exp Physiol 2020; 105:1000-1011. [DOI: 10.1113/ep088468] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 04/01/2020] [Indexed: 11/08/2022]
Affiliation(s)
- S. Walker
- NeuroMuscular Research Center Faculty of Sport and Health Sciences University of Jyväskylä Jyväskylä FI‐40014 Finland
| | - H. Piitulainen
- NeuroMuscular Research Center Faculty of Sport and Health Sciences University of Jyväskylä Jyväskylä FI‐40014 Finland
- Department of Neuroscience and Biomedical Engineering School of Science Aalto University Espoo Finland
| | - T. Manlangit
- NeuroMuscular Research Center Faculty of Sport and Health Sciences University of Jyväskylä Jyväskylä FI‐40014 Finland
| | - J. Avela
- NeuroMuscular Research Center Faculty of Sport and Health Sciences University of Jyväskylä Jyväskylä FI‐40014 Finland
| | - S. N. Baker
- Institute of Neuroscience, Medical School Newcastle University Newcastle upon Tyne UK
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32
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Mendonca GV, Mouro M, Vila-Chã C, Pezarat-Correia P. Nerve conduction during acute blood-flow restriction with and without low-intensity exercise Nerve conduction and blood-flow restriction. Sci Rep 2020; 10:7380. [PMID: 32355236 PMCID: PMC7193597 DOI: 10.1038/s41598-020-64379-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 02/07/2020] [Indexed: 11/09/2022] Open
Abstract
Despite being apparently safe for most individuals, the impact of low intensity (LI) blood-flow restricted (BFR) exercise on nerve function and integrity is still obscure. We explored whether BFR (with and without exercise) alters the properties of nerve conduction measured at the level of the restricted limb. Thirteen healthy, young men (22.0 ± 1.7 years) were included in this study. Arterial occlusion pressure was taken at rest. Soleus M- and H-recruitment curves were constructed for all participants. H-wave latencies and amplitudes were obtained in three testing conditions (non-BFR vs. 60 vs. 80% BFR) at four different time points: [#1] non-restricted baseline, [#2] time control either with or without BFR, [#3] non-restricted pre-exercise, [#4] LI exercise either with or without BFR. Nerve conduction was estimated using the difference between the latency of H and M wave. BFR did not affect H-wave amplitude, either with or without exercise. The changes in the difference between H- and M-wave latency of over time were similar between all conditions (condition-by-time interaction: F = 0.7, p = 0.47). In conclusion, our data indicate that performing LI exercise with BFR, set at 60 or 80% BFR, does not exert a negative impact on sciatic-tibial nerve function. Thus, from a neurological standpoint, we provide preliminary evidence that LI BFR exercise may be regarded as a safe mode of resistance training in healthy young men.
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Affiliation(s)
- Goncalo V Mendonca
- Neuromuscular Research Lab, Faculdade de Motricidade Humana, Universidade de Lisboa, Estrada da Costa, 1499-002, Cruz Quebrada, Dafundo, Portugal. .,CIPER, Faculdade de Motricidade Humana, Universidade de Lisboa, Estrada da Costa, 1499-002, Cruz Quebrada, Dafundo, Portugal.
| | - Miguel Mouro
- Neuromuscular Research Lab, Faculdade de Motricidade Humana, Universidade de Lisboa, Estrada da Costa, 1499-002, Cruz Quebrada, Dafundo, Portugal
| | - Carolina Vila-Chã
- Polytechnic Institute of Guarda, Av. Dr. Francisco Sá Carneiro, n. 50, Guarda, 6300-559, Portugal.,Research Center in Sports Sciences, Health and Human Development (CIDESD), Vila-Real, Portugal
| | - Pedro Pezarat-Correia
- Neuromuscular Research Lab, Faculdade de Motricidade Humana, Universidade de Lisboa, Estrada da Costa, 1499-002, Cruz Quebrada, Dafundo, Portugal.,CIPER, Faculdade de Motricidade Humana, Universidade de Lisboa, Estrada da Costa, 1499-002, Cruz Quebrada, Dafundo, Portugal
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Modulation of spinal cord excitability following remote limb ischemic preconditioning in healthy young men. Exp Brain Res 2020; 238:1265-1276. [PMID: 32303809 DOI: 10.1007/s00221-020-05807-w] [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: 11/28/2019] [Accepted: 04/08/2020] [Indexed: 12/20/2022]
Abstract
Remote limb ischemic preconditioning (RIPC) has shown to improve dynamic postural control in humans. However, studies on the underlying adaptations of spinal cord networks have never been performed. The present work addresses this issue by investigating parameters from the soleus H-reflex recruitment curve (RC), presynaptic mechanisms of reflex modulation (presynaptic inhibition-PSI, and post activation depression-PAD), and the excursion of the center of pressure (CP) recorded during 1 min in upright stance over a compliant surface. A sham ischemic protocol (partial obstruction of blood flow) was applied to the contralateral thigh along four consecutive days. The same procedure was repeated with full obstruction (RIPC) three days after ending the sham protocol. Data were collected before and after both sham and RIPC protocols. The follow-up data were collected five days after the last ischemic intervention. Significant reduction was detected for both the fast oscillations of the CP (higher frequency components) and the parameter estimated from the RC corresponding to the high amplitude H-reflexes (p < 0.05). Even though the magnitude of effects was similar, it was washed out within three days after sham, but persisted for at least five days after RIPC. No significant differences were found for PSI and PAD levels across conditions. These findings indicate that RIPC leads to enduring changes in spinal cord excitability for the latest reflexively recruited motoneurons, along with improvement in balance control. However, these adaptations were not mediated by the presynaptic mechanisms currently assessed.
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Changes in the quadriceps spinal reflex pathway after repeated sprint cycling are not influenced by ischemic preconditioning. Eur J Appl Physiol 2020; 120:1189-1202. [PMID: 32239310 DOI: 10.1007/s00421-020-04359-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 03/24/2020] [Indexed: 12/11/2022]
Abstract
PURPOSE We examined the effect of ischemic preconditioning (IPC) on changes in muscle force, activation, and the spinal reflex pathway during and after repeated sprint cycling. METHODS Eight recreationally active men (high-intensity cardiorespiratory training > 3 times per week, > 6 months) completed two exercise sessions (5 sets of 5 cycling sprints, 150% max W), preceded by either IPC (3 × 5 min leg occlusions at 220 mmHg) or SHAM (3 × 5 min at 20 mmHg). Knee extensor maximal force and rate of force were measured before (PRE), immediately post (POST), 1H, and 24H after cycling. Twitch interpolation and resting potentiated twitches were applied to estimate voluntary activation and muscle contractility, respectively. Quadriceps H-reflex recruitment curves were collected at all time-points using 10 Hz doublet stimulation to allow estimation of H-reflex post-activation depression. Surface electromyograms and tissue oxygenation (via near-infrared spectroscopy) were continuously recorded during cycling. RESULTS IPC did not affect any measure of neuromuscular function or performance during cycling. Maximal force and muscle contractility were significantly lower at POST and 1H compared to PRE and 24H by up to 50% (p < 0.01). Maximal force was lower than PRE at 24H by 8.7% (p = 0.028). Voluntary activation and rate of force were unchanged. A rightwards shift was observed for the H-reflex recruitment curve POST, and post-activation depression was higher than all other time-points at 24H (p < 0.05). Muscle activation and oxygenation decreased during cycling. CONCLUSIONS IPC has a nominal effect on mechanisms associated with neuromuscular function during and after exercise in healthy populations.
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Effects of military basic training on VO2max, body composition, muscle strength and neural responses in conscripts of different aerobic condition. BIOMEDICAL HUMAN KINETICS 2019. [DOI: 10.2478/bhk-2019-0023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Summary
Study aim: The purpose of this study was to evaluate neuromuscular adaptations in conscripts with different fitness levels (VO2max) during 8 weeks of military basic training (BT).
Material and methods: Twenty-four male conscripts (18–21 years) were divided into two groups (Good Fitness [GF] and Low fitness [LF]) based on their VO2max at the beginning of BT. Body mass (BM), fat free mass (FFM) and Fat% were measured after 2, 4, and 7 weeks of training. VO2max, maximal isometric leg press force (MVC), H-reflex (Hmax/Mmax) at rest and V-wave (V/Mmax) during maximal isometric plantarflexion were measured from the soleus muscle at the beginning, after 5, and after 8 weeks of training.
Results: FFM decreased significantly in LF after 7 weeks of training (–3.0 ± 1.7%, p < 0.001), which was not observed in GF. Both GF (6.9 ± 4.6%, p < 0.01) and LF (5.7 ± 4.6%, p < 0.01) showed improved VO2max after 5 weeks, with no changes during the last 3 weeks. A main effect of training was observed in decreased leg press MVC (–7.3 ± 9.3%, F = 4.899, p < 0.05), with no between-group differences. V-wave was significantly lower in LF during 5 (–37.9%, p < 0.05) and 8 (–44.9%, p < 0.05) weeks.
Conclusion: Poor development of the neuromuscular system during BT suggests that explosive and/or maximal strength training should be added to the BT protocol for all conscripts regardless of fitness level. In addition, individualized training periodization should be considered to optimize the training load.
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Ramos-Campo DJ, Martínez-Guardado I, Rubio-Arias JA, Freitas TT, Othalawa S, Andreu L, Timón R, Alcaraz PE. Muscle Architecture and Neuromuscular Changes After High-Resistance Circuit Training in Hypoxia. J Strength Cond Res 2019; 35:3035-3040. [PMID: 31524779 DOI: 10.1519/jsc.0000000000003275] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Ramos-Campo, DJ, Martínez-Guardado, I, Rubio-Arias, JA, Freitas, TT, Othalawa, S, Andreu, L, Timón, R, and Alcaraz, PE. Muscle architecture and neuromuscular changes after high-resistance circuit training in hypoxia. J Strength Cond Res XX(X): 000-000, 2019-This study aimed to analyze the effect of 8 weeks of high-resistance circuit (HRC) training in hypoxia on muscle architecture, strength, and neuromuscular variables. Twenty-eight resistance-trained subjects were assigned to a hypoxia (FiO2 = 15%; HG: n = 15; age: 24.6 ± 6.8 years; height: 177.4 ± 5.9 cm; and mass: 74.9 ± 11.5 kg) or normoxia group (FiO2 = 20.9%; NG: n = 13; age: 23.2 ± 5.2 years; height: 173.4 ± 6.2 cm; and mass: 69.4 ± 7.4 kg). Each training session consisted of 2 blocks of 3 exercises (block 1: bench press, leg extension, and front lat pulldown; block 2: deadlift, elbow flexion, and ankle extension). Each exercise was performed with a 6 repetition maximum load. Subjects exercised twice weekly and, before and after the training program, vastus lateralis muscle thickness and pennation angle, knee extensors electromyographic activity, maximum voluntary contraction (MVC), and rate of force development (RFD) and H-Reflex (Hmax), M-wave of the soleus muscle were assessed. Both training groups showed similar improvements in muscle thickness (effect size [ES] = HG: 0.23; NG: 0.41), pennation angle (ES = HG: 0.86; NG: 0.15), MVC (ES HG: 0.63; NG: 0.61), Hmax (ES = HG: 0.96; NG: 0.40), RFD at 200 milliseconds (ES = HG: 0.31; NG: 0.61) and peak RFD (ES = HG: 0.21; NG: 0.66). No significant between-group differences were found. In conclusion, similar morphological and neuromuscular adaptations can be achieved after 8 weeks of HRC training under hypoxic or normoxic conditions.
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Affiliation(s)
- Domingo J Ramos-Campo
- Sport Science Faculty, Catholic University of Murcia, Murcia, Spain.,UCAM Research Center for High Performance Sport, Murcia, Spain
| | | | - Jacobo A Rubio-Arias
- Sport Science Faculty, Catholic University of Murcia, Murcia, Spain.,UCAM Research Center for High Performance Sport, Murcia, Spain
| | - Tomás T Freitas
- UCAM Research Center for High Performance Sport, Murcia, Spain
| | | | - Luis Andreu
- UCAM Research Center for High Performance Sport, Murcia, Spain
| | - Rafael Timón
- Sport Science Faculty, University of Extremadura, Cáceres, Spain
| | - Pedro E Alcaraz
- Sport Science Faculty, Catholic University of Murcia, Murcia, Spain.,UCAM Research Center for High Performance Sport, Murcia, Spain
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Silva-Batista C, Lira JLDO, David FJ, Corcos DM, Mattos ECT, Boari Coelho D, de Lima-Pardini AC, Torriani-Pasin C, de Freitas TB, Ugrinowitsch C. Short-term resistance training with instability reduces impairment in V wave and H reflex in individuals with Parkinson's disease. J Appl Physiol (1985) 2019; 127:89-97. [PMID: 31306047 DOI: 10.1152/japplphysiol.00902.2018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This study had two objectives: 1) to compare the effects of 3 wk of resistance training (RT) and resistance training with instability (RTI) on evoked reflex responses at rest and during maximal voluntary isometric contraction (MVIC) of individuals with Parkinson's disease (PD) and 2) to determine the effectiveness of RT and RTI in moving values of evoked reflex responses of individuals with PD toward values of age-matched healthy control subjects (HCs) (z-score analysis). Ten individuals in the RT group and 10 in the RTI group performed resistance exercises twice a week for 3 wk, but only the RTI group included unstable devices. The HC group (n = 10) were assessed at pretest only. Evoked reflex responses at rest (H reflex and M wave) and during MVIC [supramaximal M-wave amplitude (Msup) and supramaximal V-wave amplitude (Vsup)] of the plantar flexors were assessed before and after the experimental protocol. From pretraining to posttraining, only RTI increased ratio of maximal H-reflex amplitude to maximal M-wave amplitude at rest (Hmax/Mmax), Msup, Vsup/Msup, and peak torque of the plantar flexors (P < 0.05). At posttraining, RTI was more effective than RT in increasing resting Hmax and Vsup and in moving these values to those observed in HCs (P < 0.05). We conclude that short-term RTI is more effective than short-term RT in modulating H-reflex excitability and in increasing efferent neural drive, approaching average values of HCs. Thus short-term RTI may cause positive changes at the spinal and supraspinal levels in individuals with PD. NEW & NOTEWORTHY Maximal H-reflex amplitude (Hmax) at rest and efferent neural drive [i.e., supramaximal V-wave amplitude (Vsup)] to skeletal muscles during maximal contraction are impaired in individuals with Parkinson's disease. Short-term resistance training with instability was more effective than short-term resistance training alone in increasing Hmax and Vsup of individuals with Parkinson's disease, reaching the average values of healthy control subjects.
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Affiliation(s)
- Carla Silva-Batista
- Exercise Neuroscience Research Group, School of Arts, Sciences and Humanities, University of São Paulo , São Paulo , Brazil.,Laboratory of Adaptations to Strength Training, School of Physical Education and Sport, University of São Paulo at São Paulo , São Paulo , Brazil
| | | | - Fabian J David
- Department of Physical Therapy and Human Movement Sciences, Northwestern University , Chicago, Illinois
| | - Daniel M Corcos
- Department of Physical Therapy and Human Movement Sciences, Northwestern University , Chicago, Illinois.,Department of Neurological Sciences, Rush University Medical Center , Chicago, Illinois
| | - Eugenia Casella Tavares Mattos
- Exercise Neuroscience Research Group, School of Arts, Sciences and Humanities, University of São Paulo , São Paulo , Brazil
| | - Daniel Boari Coelho
- Biomedical Engineering, Federal University of ABC , São Bernardo do Campo, São Paulo , Brazil.,Department of Neuroscience, Federal University of ABC , São Paulo , Brazil
| | - Andrea C de Lima-Pardini
- Laboratory of Adaptations to Strength Training, School of Physical Education and Sport, University of São Paulo at São Paulo , São Paulo , Brazil.,Department of Neuroscience, Federal University of ABC , São Paulo , Brazil
| | - Camila Torriani-Pasin
- Department of Pedagogy of the Human Body, Laboratory of Motor Behavior, School of Physical Education and Sports, University of São Paulo , São Paulo , Brazil
| | - Tatiana Beline de Freitas
- Department of Pedagogy of the Human Body, Laboratory of Motor Behavior, School of Physical Education and Sports, University of São Paulo , São Paulo , Brazil
| | - Carlos Ugrinowitsch
- Laboratory of Adaptations to Strength Training, School of Physical Education and Sport, University of São Paulo at São Paulo , São Paulo , Brazil
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Piirainen JM, Rautio T, Tanskanen-Tervo MM, Kyröläinen H, Huovinen J, Linnamo V. Effects of 10 weeks of military training on neuromuscular function in non-overreached and overreached conscripts. J Electromyogr Kinesiol 2019; 47:43-48. [PMID: 31108348 DOI: 10.1016/j.jelekin.2019.05.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 04/26/2019] [Accepted: 05/10/2019] [Indexed: 11/26/2022] Open
Abstract
The purpose of the study was to examine how military training influences neuromuscular function in non-overreached and overreached conscripts. A total of 24 male conscripts participated in the study (8 weeks basic training + 2 weeks specialized training). All measurements were conducted during weeks 1, 5, 8 and 10. After the training period, non-overreached (NOR, n = 16) and overreached (OR, n = 8) groups were compared. Isometric maximal forces (bench press, elbow flexion and knee extension), single twitch (plantar flexors), H-reflex, M-wave (Hmax/Mmax) and V-wave (V/Mmax) (soleus) were measured. In knee extension, force production increased in NOR by 22.5 ± 20.5% (p < 0.01) between weeks 1 and 8, which was not observed in OR (-1.1 ± 18.2%, p > 0.05). In OR, plantarflexion twitch contraction time increased between weeks 5 and 10 by 82.2 ± 34.4% (p < 0.01), which was not observed in NOR. No changes were observed in the H-reflex and V-wave responses in either of the groups. In conclusion, short term overreaching can also reduce the performance of the neuromuscular system, however, it seems to be more muscle than neural based. To avoid overreaching, more individualized periodization should be used during basic training. To enhance neuromuscular performance, maximal and explosive strength training should also be added into the basic training program.
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Affiliation(s)
- J M Piirainen
- Neuromuscular Research Center, Biology of Physical Activity, Faculty of Sport and Health Sciences, University of Jyväskylä, Finland.
| | - T Rautio
- Neuromuscular Research Center, Biology of Physical Activity, Faculty of Sport and Health Sciences, University of Jyväskylä, Finland
| | - M M Tanskanen-Tervo
- Neuromuscular Research Center, Biology of Physical Activity, Faculty of Sport and Health Sciences, University of Jyväskylä, Finland
| | - H Kyröläinen
- Neuromuscular Research Center, Biology of Physical Activity, Faculty of Sport and Health Sciences, University of Jyväskylä, Finland
| | - J Huovinen
- Neuromuscular Research Center, Biology of Physical Activity, Faculty of Sport and Health Sciences, University of Jyväskylä, Finland
| | - V Linnamo
- Neuromuscular Research Center, Biology of Physical Activity, Faculty of Sport and Health Sciences, University of Jyväskylä, Finland
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40
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Huang TH, Chou LW, Huang CY, Wei SW, Tsai YJ, Chen YJ. H-reflex in abductor hallucis and postural performance between flexible flatfoot and normal foot. Phys Ther Sport 2019; 37:27-33. [PMID: 30818085 DOI: 10.1016/j.ptsp.2019.02.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 02/14/2019] [Accepted: 02/14/2019] [Indexed: 01/13/2023]
Abstract
OBJECTIVE Morphological changes of the abductor hallucis muscle (AbH) in flexible flatfoot (FF) individuals influence regulations of the medial longitudinal arch (MLA). Prolonged and repeated stretching of AbH in flexible flatfoot may cause changes in muscle reflex properties and further influence postural performance. However, AbH muscle reflex under different postural conditions have never been examined. The purpose of this study was to investigate differences in AbH H-reflex and postural performance between individuals with normal foot (NF) alignment and FF under prone, double-leg stance (DLS), and single-leg stance (SLS) conditions. DESIGN Cross-sectional study. SETTING University laboratory. PARTICIPANTS Individuals with FF (n = 12) and NF (n = 12). MAIN OUTCOME MEASURES AbH H-reflex, AbH EMG and center of pressure (CoP) displacement. RESULTS Under all postural conditions, AbH H-reflex was significantly lower in the FF group (P < .05). Under the SLS condition, AbH EMG was significantly higher in the FF group (P < .05), and CoP displacement for the medial-lateral and anterior-posterior directions were significantly higher in the FF group (P < .05). CONCLUSIONS With increased postural demand, FF individuals maintained their postural stability by recruiting greater AbH activities than through automatic stretch reflex, but FF individuals still showed inferior posture stability.
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Affiliation(s)
- Tzu-Hui Huang
- School and Graduate Institute of Physical Therapy, College of Medicine, National Taiwan University, Floor 3, No.17, Xuzhou Rd., Zhongzheng District, Taipei City, 100, Taiwan, ROC.
| | - Li-Wei Chou
- Department of Physical Therapy and Assistive Technology, National Yang-Ming University, No.155, Sec.2, Linong Street, Taipei, 112, Taiwan, ROC.
| | - Cheng-Ya Huang
- School and Graduate Institute of Physical Therapy, College of Medicine, National Taiwan University, Floor 3, No.17, Xuzhou Rd., Zhongzheng District, Taipei City, 100, Taiwan, ROC.
| | - Shun-Wa Wei
- Department of Physical Therapy and Assistive Technology, National Yang-Ming University, No.155, Sec.2, Linong Street, Taipei, 112, Taiwan, ROC.
| | - Yi-Ju Tsai
- Department of Physical Therapy, National Cheng-Kung University, No.1, Ta-Hsueh Road, Tainan, 701, Taiwan, ROC.
| | - Yu-Jen Chen
- School and Graduate Institute of Physical Therapy, College of Medicine, National Taiwan University, Floor 3, No.17, Xuzhou Rd., Zhongzheng District, Taipei City, 100, Taiwan, ROC; Department of Physical Education, Fu Jen Catholic University, No.510, Zhongzheng Rd., Xinzhuang Dist., New Taipei City, 24205, Taiwan, ROC.
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Holt K, Niazi IK, Nedergaard RW, Duehr J, Amjad I, Shafique M, Anwar MN, Ndetan H, Turker KS, Haavik H. The effects of a single session of chiropractic care on strength, cortical drive, and spinal excitability in stroke patients. Sci Rep 2019; 9:2673. [PMID: 30804399 PMCID: PMC6389925 DOI: 10.1038/s41598-019-39577-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 01/25/2019] [Indexed: 12/11/2022] Open
Abstract
The objective of this study was to investigate whether a single session of chiropractic care could increase strength in weak plantar flexor muscles in chronic stroke patients. Maximum voluntary contractions (strength) of the plantar flexors, soleus evoked V-waves (cortical drive), and H-reflexes were recorded in 12 chronic stroke patients, with plantar flexor muscle weakness, using a randomized controlled crossover design. Outcomes were assessed pre and post a chiropractic care intervention and a passive movement control. Repeated measures ANOVA was used to asses within and between group differences. Significance was set at p < 0.05. Following the chiropractic care intervention there was a significant increase in strength (F (1,11) = 14.49, p = 0.002; avg 64.2 ± 77.7%) and V-wave/Mmax ratio (F(1,11) = 9.67, p = 0.009; avg 54.0 ± 65.2%) compared to the control intervention. There was a significant strength decrease of 26.4 ± 15.5% (p = 0.001) after the control intervention. There were no other significant differences. Plantar flexor muscle strength increased in chronic stroke patients after a single session of chiropractic care. An increase in V-wave amplitude combined with no significant changes in H-reflex parameters suggests this increased strength is likely modulated at a supraspinal level. Further research is required to investigate the longer term and potential functional effects of chiropractic care in stroke recovery.
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Affiliation(s)
- Kelly Holt
- Centre for Chiropractic Research, New Zealand College of Chiropractic, Auckland, New Zealand
| | - Imran Khan Niazi
- Centre for Chiropractic Research, New Zealand College of Chiropractic, Auckland, New Zealand
- Health & Rehabilitation Research Institute, Auckland University of Technology, Auckland, New Zealand
- SMI, Department of Health Science and Technology, Aalborg University, Aalborg, Denmark
| | | | - Jens Duehr
- Centre for Chiropractic Research, New Zealand College of Chiropractic, Auckland, New Zealand
| | - Imran Amjad
- Riphah International University, Islamabad, Pakistan
| | | | | | - Harrison Ndetan
- University of North Texas Health Science Center, Tylers, Texas, USA
| | | | - Heidi Haavik
- Centre for Chiropractic Research, New Zealand College of Chiropractic, Auckland, New Zealand.
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Walker S, Avela J, Wikgren J, Meeusen R, Piitulainen H, Baker SN, Parviainen TM. Aging and Strength Training Influence Knee Extensor Intermuscular Coherence During Low- and High-Force Isometric Contractions. Front Physiol 2019; 9:1933. [PMID: 30728782 PMCID: PMC6351450 DOI: 10.3389/fphys.2018.01933] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Accepted: 12/21/2018] [Indexed: 12/11/2022] Open
Abstract
Aging is associated with reduced maximum force production and force steadiness during low-force tasks, but both can be improved by training. Intermuscular coherence measures coupling between two peripheral surface electromyography (EMG) signals in the frequency domain. It is thought to represent the presence of common input to alpha-motoneurons, but the functional meaning of intermuscular coherence, particularly regarding aging and training, remain unclear. This study investigated knee extensor intermuscular coherence in previously sedentary young (18–30 years) and older (67–73 years) subjects before and after a 14-week strength training intervention. YOUNG and OLDER groups performed maximum unilateral isometric knee extensions [100% maximum voluntary contraction (MVC)], as well as force steadiness tests at 20 and 70% MVC, pre- and post-training. Intermuscular (i.e., EMG-EMG) coherence analyses were performed for all (three) contraction intensities in vastus lateralis and medialis muscles. Pre-training coefficient of force variation (i.e., force steadiness) and MVC (i.e., maximum torque) were similar between groups. Both groups improved MVC through training, but YOUNG improved more than OLDER (42 ± 27 Nm versus 18 ± 16 Nm, P = 0.022). Force steadiness did not change during 20% MVC trials in either group, but YOUNG demonstrated increased coefficient of force variation during 70% MVC trials (1.28 ± 0.46 to 1.57 ± 0.70, P = 0.01). YOUNG demonstrated greater pre-training coherence during 20% and 70% MVC trials, particularly within the 8–14 Hz (e.g., 20%: 0.105 ± 0.119 versus 0.016 ± 0.009, P = 0.001) and 16–30 Hz (20%: 0.063 ± 0.078 versus 0.012 ± 0.007, P = 0.002) bands, but not during 100% MVC trials. Strength training led to increases in intermuscular coherence within the 40–60 Hz band during 70% MVC trials in YOUNG only, while OLDER decreased within the 8–14 Hz band during 100% MVC trials. Age-related differences in intermuscular coherence were observed between young and older individuals, even when neuromuscular performance levels were similar. The functional significance of intermuscular coherence remains unclear, since coherence within different frequency bands did not explain any of the variance in the regression models for maximum strength or force steadiness during 20 and 70% MVC trials.
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Affiliation(s)
- Simon Walker
- Neuromuscular Research Center, Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland
| | - Janne Avela
- Neuromuscular Research Center, Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland
| | - Jan Wikgren
- Department of Psychology, Centre for Interdisciplinary Brain Research, Faculty of Education and Psychology, University of Jyväskylä, Jyväskylä, Finland
| | - Romain Meeusen
- Human Physiology Research Group, Vrije Universiteit Brussel, Brussels, Belgium
| | - Harri Piitulainen
- Neuromuscular Research Center, Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland.,Department of Neuroscience and Biomedical Engineering, Aalto University, Espoo, Finland
| | - Stuart N Baker
- Institute of Neuroscience, Medical School, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Tiina M Parviainen
- Department of Psychology, Centre for Interdisciplinary Brain Research, Faculty of Education and Psychology, University of Jyväskylä, Jyväskylä, Finland
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Metcalf E, Hagstrom AD, Marshall PW. Trained females exhibit less fatigability than trained males after a heavy knee extensor resistance exercise session. Eur J Appl Physiol 2018; 119:181-190. [PMID: 30324418 DOI: 10.1007/s00421-018-4013-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 10/11/2018] [Indexed: 12/25/2022]
Abstract
PURPOSE We examined differences between trained males and females in measures of muscular fatigability and central motor output after a resistance exercise session. METHODS Sixteen trained males (n = 8) and females (n = 8) participated in the study. Knee extensor maximal torque and rate of torque development were measured before and after the exercise session, and the twitch interpolation technique was used during the maximal efforts to derive measures of voluntary activation and muscle contractility by supramaximal stimulation of the femoral nerve using 10 and 100 Hz doublets. Surface electromyograms were recorded during all maximal efforts to examine maximal and rate of quadriceps muscle activation. RESULTS After exercise, maximal torque was reduced for both sexes by 26.3 ± 12.5% (p < 0.001). Absolute and relative vRTD was reduced only for males after exercise (p < 0.05). The early (0-50 ms) rate of muscle activation rise was similarly reduced for both sexes between 2.6 and 16.4% s-1 (p < 0.01), but males experienced an average decrease of 82.5 ± 72.1% s-1 for the maximal rate of muscle activation compared to no change for females (p = 0.02). Males had greater reductions (p < 0.05) for maximal twitch amplitudes and rate of twitch development (- 51.1 ± 21.5% and - 49.9 ± 22.8%, respectively) compared to females (- 35.8 ± 13.7% and - 31.5 ± 14.0%, respectively). CONCLUSIONS These findings suggest that trained females are resistant to reductions in rapid torque development, despite similar reductions in maximal torque, after resistance exercise, with this result explained by better-maintained muscle contractility and maximal rate of muscle activation compared to males.
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Affiliation(s)
- Emily Metcalf
- Human Performance Laboratory, Western Sydney University, Penrith, Australia
| | - Amanda D Hagstrom
- School of Science and Technology, University of New England, Armidale, Australia
| | - Paul W Marshall
- Human Performance Laboratory, Western Sydney University, Penrith, Australia.
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Barss TS, Klarner T, Pearcey GEP, Sun Y, Zehr EP. Time course of interlimb strength transfer after unilateral handgrip training. J Appl Physiol (1985) 2018; 125:1594-1608. [PMID: 30188797 DOI: 10.1152/japplphysiol.00390.2017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
"Cross-education" is the increase in strength or functional performance of an untrained limb after unilateral training. A major limitation for clinical translation from unilateral injury includes knowledge on the minimum time for the emergence of crossed effects. Therefore, the primary purpose was to characterize the time course of bilateral strength changes during both "traditional" ( n = 11) and "daily" ( n = 8) unilateral handgrip training in neurologically intact participants. Traditional training included five sets of five maximal voluntary handgrip contractions 3 times/wk for 6 wk whereas daily training included the same number of sessions and contractions but over 18 consecutive days. Three pre- and one posttest session evaluated strength, muscle activation, and reflex excitability bilaterally. Time course information was assessed by recording handgrip force for every contraction in the trained limb and from a single contraction on every third training session in the untrained limb. Six weeks of traditional training increased handgrip strength in the trained limb after the 9th session whereas the untrained limb was stronger after the 12th session. This was accompanied by increased peak muscle activation and bilateral alterations in Hoffmann reflex excitability. Daily training revealed a similar number of sessions (15) were required to induce significant strength gains in the untrained limb (7.8% compared with 12.5%) in approximately half the duration of traditional training. Therefore, minimizing rest days may improve the efficiency of unilateral training when the trained limb is not the focus. Establishing a "dose" for the time course of adaptation to strength training is paramount for effective translation to rehabilitative interventions. NEW & NOTEWORTHY Unilateral handgrip training using a "traditional" protocol (3 times/wk; 6 wk) increased strength bilaterally after 9 (trained arm) and 12 (untrained arm) sessions. "Daily" training (18 consecutive days) increased strength in the untrained limb in a similar number of training sessions, which was accomplished in approximately half the time. Within clinical populations when the focus is on the untrained limb, reducing rest days may optimize the recovery of strength.
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Affiliation(s)
- Trevor S Barss
- Rehabilitation Neuroscience Laboratory, University of Victoria , Victoria, British Columbia , Canada.,Human Discovery Science, International Collaboration on Repair Discoveries , Vancouver, British Columbia , Canada.,Centre for Biomedical Research, University of Victoria , Victoria, British Columbia , Canada
| | - Taryn Klarner
- Rehabilitation Neuroscience Laboratory, University of Victoria , Victoria, British Columbia , Canada.,Human Discovery Science, International Collaboration on Repair Discoveries , Vancouver, British Columbia , Canada.,Centre for Biomedical Research, University of Victoria , Victoria, British Columbia , Canada.,School of Kinesiology, Lakehead University , Thunder Bay, Ontario , Canada
| | - Gregory E P Pearcey
- Rehabilitation Neuroscience Laboratory, University of Victoria , Victoria, British Columbia , Canada.,Human Discovery Science, International Collaboration on Repair Discoveries , Vancouver, British Columbia , Canada.,Centre for Biomedical Research, University of Victoria , Victoria, British Columbia , Canada
| | - Yao Sun
- Rehabilitation Neuroscience Laboratory, University of Victoria , Victoria, British Columbia , Canada.,Human Discovery Science, International Collaboration on Repair Discoveries , Vancouver, British Columbia , Canada.,Centre for Biomedical Research, University of Victoria , Victoria, British Columbia , Canada
| | - E Paul Zehr
- Rehabilitation Neuroscience Laboratory, University of Victoria , Victoria, British Columbia , Canada.,Human Discovery Science, International Collaboration on Repair Discoveries , Vancouver, British Columbia , Canada.,Centre for Biomedical Research, University of Victoria , Victoria, British Columbia , Canada.,Division of Medical Sciences, University of Victoria , Victoria, British Columbia , Canada
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Effects of endurance training on neuromuscular fatigue in healthy active men. Part I: Strength loss and muscle fatigue. Eur J Appl Physiol 2018; 118:2281-2293. [PMID: 30121882 DOI: 10.1007/s00421-018-3950-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 07/23/2018] [Indexed: 01/26/2023]
Abstract
PURPOSE The adaptations induced by endurance training on the neuromuscular function remain under investigation and, for methodological reasons, unclear. This study investigates the effects of cycling training on neuromuscular fatigue and its peripheral contribution measured during and immediately after cycling exercise. METHODS Fourteen healthy men performed a fatigue test before a 9-week cycling program (PRE) and two tests after training: at the same absolute power output as PRE (POSTABS) and based on the post-training maximal aerobic power (POSTREL). Throughout the tests and at exhaustion (EXH), maximal voluntary contraction (MVC) and peripheral fatigue were assessed in the quadriceps muscle by electrical nerve stimulation [single twitch (Pt); high-frequency doublet (Db100) and low-to-high-frequency ratio (Db10:100)]. RESULTS Time to EXH was longer in POSTABS than PRE (34 ± 5 vs. 27 ± 4 min, P < 0.001), and POSTREL tended to be longer than PRE (30 ± 6 min, P = 0.053). MVC and peripheral fatigue were overall less depressed in POSTABS than PRE at isotime. At EXH, MVC and Db10:100 were similarly reduced in all sessions (-37 to - 42% and - 30 to - 37%, respectively). Db100 tended to be less depressed in POSTABS than PRE (-40 ± 9 vs. - 48 ± 16%, P = 0.050) and in POSTREL than PRE (-39 ± 9%, P = 0.071). Pt decreased similarly in POSTABS and PRE (-52 ± 16 vs. - 54 ± 16%), but POSTREL tended to be less depressed than PRE (-48 ± 14%, P = 0.075). CONCLUSIONS This study confirms fatigue attenuation at isotime after training. Yet lower or similar fatigue at EXH indicates that, unlike previously suggested, fatigue tolerance may not be upregulated after 9 weeks of cycling training.
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Aagaard P. Spinal and supraspinal control of motor function during maximal eccentric muscle contraction: Effects of resistance training. JOURNAL OF SPORT AND HEALTH SCIENCE 2018; 7:282-293. [PMID: 30356634 PMCID: PMC6189238 DOI: 10.1016/j.jshs.2018.06.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/28/2018] [Revised: 03/22/2018] [Accepted: 03/24/2018] [Indexed: 06/08/2023]
Abstract
Neuromuscular activity is suppressed during maximal eccentric (ECC) muscle contraction in untrained subjects owing to attenuated levels of central activation and reduced spinal motor neuron (MN) excitability indicated by reduced electromyography signal amplitude, diminished evoked H-reflex responses, increased autogenic MN inhibition, and decreased excitability in descending corticospinal motor pathways. Maximum ECC muscle force recorded during maximal voluntary contraction can be increased by superimposed electrical muscle stimulation only in untrained individuals and not in trained strength athletes, indicating that the suppression in MN activation is modifiable by resistance training. In support of this notion, maximum ECC muscle strength can be increased by use of heavy-load resistance training owing to a removed or diminished suppression in neuromuscular activity. Prolonged (weeks to months) of heavy-load resistance training results in increased H-reflex and V-wave responses during maximal ECC muscle actions along with marked gains in maximal ECC muscle strength, indicating increased excitability of spinal MNs, decreased presynaptic and/or postsynaptic MN inhibition, and elevated descending motor drive. Notably, the use of supramaximal ECC resistance training can lead to selectively elevated V-wave responses during maximal ECC contraction, demonstrating that adaptive changes in spinal circuitry function and/or gains in descending motor drive can be achieved during maximal ECC contraction in response to heavy-load resistance training.
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Hight RE, Quarshie AT, Black CD. Voluntary muscle activation and evoked volitional-wave responses as a function of torque. J Electromyogr Kinesiol 2018; 41:1-8. [PMID: 29709787 DOI: 10.1016/j.jelekin.2018.04.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 02/28/2018] [Accepted: 04/14/2018] [Indexed: 10/17/2022] Open
Abstract
INTRODUCTION This study employed a unique stimulation paradigm which allowed for the simultaneous assessment of voluntary activation levels (VA) via twitch-interpolation, and the evoked V-wave responses of the plantar flexors during submaximal and maximal contractions. Test-retest reliability was also examined. METHODS Fourteen participants repeated a stimulation protocol over four visits to assess VA and evoked V-wave amplitude across torque levels ranging from 20% to 100% MVC. MVC torque and EMG amplitude were also measured. RESULTS VA increased nonlinearly with torque production and plateaued by 80% MVC. V-wave amplitude increased linearly from 20% to 100% MVC. There were no differences in any dependent variable across visits (p > 0.05). VA demonstrated moderate to substantial reliability across all torque levels (ICC = 0.76-0.91) while V-wave amplitude exhibited fair to moderate reliability from 40% to 100% (ICC = 0.48-0.74). DISCUSSION We were able to reliably collect VA and the V-wave simultaneously in the plantar flexors. Collection of VA and V-wave during the same contraction provides distinct information regarding the contribution of motor-unit recruitment and descending cortico-spinal drive/excitability to force production.
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Affiliation(s)
- Robert E Hight
- The Department of Health and Exercise Science, The University of Oklahoma, Norman, OK, United States.
| | - Alwyn T Quarshie
- The Department of Health and Exercise Science, The University of Oklahoma, Norman, OK, United States
| | - Christopher D Black
- The Department of Health and Exercise Science, The University of Oklahoma, Norman, OK, United States
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Giboin LS, Weiss B, Thomas F, Gruber M. Neuroplasticity following short-term strength training occurs at supraspinal level and is specific for the trained task. Acta Physiol (Oxf) 2018; 222:e12998. [PMID: 29144602 DOI: 10.1111/apha.12998] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 11/10/2017] [Accepted: 11/10/2017] [Indexed: 11/29/2022]
Abstract
AIMS Different modalities of strength training cause performance enhancements, which are specific for the trained task. However, the involved mechanisms are still largely unknown. It has been demonstrated that strength training could induce neuroplasticity, which might underlie the performance improvements during the first training sessions. Thus, we hypothesized to find task-specific neuroplasticity after a short-term strength training of two distinct strength tasks. METHODS Young healthy male subjects were exposed to 4 sessions of either maximal isometric explosive (EXPL group, N = 9) or slow sustained (SUS group, N = 10) knee extensions. Pre- and post-training, we measured H-reflexes and motor evoked potentials (MEPs) in the vastus lateralis (VL) at the onset of both strength tasks. RESULTS Pre- and post-training, H-reflexes remained unchanged in both groups. MEP areas were lower in the trained task in both groups and remained unchanged in the untrained task. CONCLUSION This study demonstrated that short-term strength training induces specific neuroplasticity for the trained task only. The fact that MEPs were lower but H-reflex amplitudes remained unchanged at the onset of the trained tasks suggests that strength training elicited neuroplasticity at supraspinal level that most likely reflect an improved task-specific corticospinal efficiency.
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Affiliation(s)
- L.-S. Giboin
- Sensorimotor Performance Lab; Department of Sport Science; University of Konstanz; Konstanz Germany
| | - B. Weiss
- Sensorimotor Performance Lab; Department of Sport Science; University of Konstanz; Konstanz Germany
| | - F. Thomas
- Sensorimotor Performance Lab; Department of Sport Science; University of Konstanz; Konstanz Germany
| | - M. Gruber
- Sensorimotor Performance Lab; Department of Sport Science; University of Konstanz; Konstanz Germany
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Christiansen TL, Niazi IK, Holt K, Nedergaard RW, Duehr J, Allen K, Marshall P, Türker KS, Hartvigsen J, Haavik H. The effects of a single session of spinal manipulation on strength and cortical drive in athletes. Eur J Appl Physiol 2018; 118:737-749. [PMID: 29327170 PMCID: PMC5843672 DOI: 10.1007/s00421-018-3799-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 01/01/2018] [Indexed: 11/11/2022]
Abstract
Purpose The primary purpose of this study was to investigate whether a single session of spinal manipulation (SM) increases strength and cortical drive in the lower limb (soleus muscle) of elite Taekwondo athletes. Methods Soleus-evoked V-waves, H-reflex and maximum voluntary contraction (MVC) of the plantar flexors were recorded from 11 elite Taekwondo athletes using a randomized controlled crossover design. Interventions were either SM or passive movement control. Outcomes were assessed at pre-intervention and at three post-intervention time periods (immediate post, post 30 min and post 60 min). A multifactorial repeated measures ANOVA was conducted to assess within and between group differences. Time and session were used as factors. A post hoc analysis was carried out, when an interactive effect was present. Significance was set at p ≤ 0.05. Results SM increased MVC force [F(3,30) = 5.95, p < 0.01], and V-waves [F(3,30) = 4.25, p = 0.01] over time compared to the control intervention. Between group differences were significant for all time periods (p < 0.05) except for the post60 force measurements (p = 0.07). Conclusion A single session of SM increased muscle strength and corticospinal excitability to ankle plantar flexor muscles in elite Taekwondo athletes. The increased MVC force lasted for 30 min and the corticospinal excitability increase persisted for at least 60 min.
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Affiliation(s)
- Thomas Lykke Christiansen
- Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark.,Nordic Institute of Chiropractic and Clinical Biomechanics, Odense, Denmark
| | - Imran Khan Niazi
- Center for Chiropractic Research, New Zealand College of Chiropractic, 6 Harrison Road, Mount Wellington, Auckland, New Zealand. .,SMI, Department of Health Science and Technology, Aalborg University, Aalborg, Denmark.
| | - Kelly Holt
- Center for Chiropractic Research, New Zealand College of Chiropractic, 6 Harrison Road, Mount Wellington, Auckland, New Zealand
| | - Rasmus Wiberg Nedergaard
- Center for Chiropractic Research, New Zealand College of Chiropractic, 6 Harrison Road, Mount Wellington, Auckland, New Zealand
| | - Jens Duehr
- Center for Chiropractic Research, New Zealand College of Chiropractic, 6 Harrison Road, Mount Wellington, Auckland, New Zealand
| | - Kathryn Allen
- Center for Chiropractic Research, New Zealand College of Chiropractic, 6 Harrison Road, Mount Wellington, Auckland, New Zealand
| | - Paul Marshall
- School of Science and Health, Western Sydney University, Sydney, Australia
| | | | - Jan Hartvigsen
- Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark.,Nordic Institute of Chiropractic and Clinical Biomechanics, Odense, Denmark
| | - Heidi Haavik
- Center for Chiropractic Research, New Zealand College of Chiropractic, 6 Harrison Road, Mount Wellington, Auckland, New Zealand
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Rodríguez-Rosell D, Pareja-Blanco F, Aagaard P, González-Badillo JJ. Physiological and methodological aspects of rate of force development assessment in human skeletal muscle. Clin Physiol Funct Imaging 2017; 38:743-762. [DOI: 10.1111/cpf.12495] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 11/29/2017] [Indexed: 12/22/2022]
Affiliation(s)
- David Rodríguez-Rosell
- Centro de Investigación en Rendimiento Físico y Deportivo, Universidad Pablo de Olavide, Seville, Spain
| | - Fernando Pareja-Blanco
- Centro de Investigación en Rendimiento Físico y Deportivo, Universidad Pablo de Olavide, Seville, Spain
| | - Per Aagaard
- Department of Sports Science and Clinical Biomechanics, SDU Muscle Research Cluster (SMRC), University of Southern Denmark, Odense, Denmark
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