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Kim KM, Kim JS, Needle AR. Soleus arthrogenic muscle inhibition following acute lateral ankle sprain correlates with symptoms and ankle disability but not with postural control. J Sport Health Sci 2024:S2095-2546(24)00022-X. [PMID: 38428732 DOI: 10.1016/j.jshs.2024.02.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 10/20/2023] [Accepted: 11/27/2023] [Indexed: 03/03/2024]
Abstract
BACKGROUND Acute lateral ankle sprains (ALAS) are associated with long-term impairments and instability tied to altered neural excitability. Arthrogenic muscle inhibition (AMI) has been observed in this population; however, relationships with injury-related impairments are unclear, potentially due to the resting, prone position in which AMI is typically measured. Assessing AMI during bipedal stance may provide a better understanding of this relationship. METHODS AMI was assessed in 38 young adults (19 ALAS within 72 h of injury: 10 males, 21.4 ± 2.7 years; 19 healthy controls: 10 males, 21.9 ± 2.2 years; mean ± SD) using the Hoffmann reflex during bipedal stance. Electrical stimulation was administered to identify the maximal H-reflex (Hmax) and maximal motor response (Mmax) from the soleus, fibularis longus, and tibialis anterior muscles. The primary outcome measure was the Hmax/Mmax ratio. Secondary outcomes included acute symptoms (pain and swelling), postural control during bipedal stance, and self-reported function. RESULTS No significant group-by-limb interactions were observed for any muscle. However, a significant group main effect was observed in the soleus muscle, F1,35 = 6.82, p = 0.013, indicating significantly lower Hmax/Mmax ratios following ALAS (0.38 ± 0.20) compared to healthy controls (0.53 ± 0.16). Furthermore, lower Hmax/Mmax ratios in the soleus significantly correlated with acute symptoms and self-reported function but not with postural control. CONCLUSION This study supports previous evidence of AMI in patients with ALAS, providing insight into neurophysiologic impacts of musculoskeletal injury. Our results suggest that assessing AMI in a standing position following acute injury may provide valuable insight into how AMI develops and guide potential therapeutic options to curb and offset the formation of joint instability.
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Affiliation(s)
- Kyung-Min Kim
- Department of Sport Science, Sungkyunkwan University, Suwon-si 16419, Republic of Korea
| | - Joo-Sung Kim
- Department of Health and Human Performance, Texas State University, San Marcos, TX 78666, USA
| | - Alan R Needle
- Department of Public Health & Exercise Science, Appalachian State University, Boone, NC 28608, USA; Department of Rehabilitation Science, Appalachian State University, Boone, NC 28608, USA.
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Kim KM, Needle AR, Kim JS, An YW, Cruz-Díaz D, Taube W. What interventions can treat arthrogenic muscle inhibition in patients with chronic ankle instability? A systematic review with meta-analysis. Disabil Rehabil 2024; 46:241-256. [PMID: 36650898 DOI: 10.1080/09638288.2022.2161643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 12/18/2022] [Indexed: 01/19/2023]
Abstract
PURPOSE To identify, critically appraise, and synthesize the existing evidence regarding the effects of therapeutic interventions on arthrogenic muscle inhibition (AMI) in patients with chronic ankle instability (CAI). MATERIALS AND METHODS Two reviewers independently performed exhaustive database searches in Web of Science, PubMed, Medline, CINAHL, and SPORTDiscus. RESULTS Nine studies were finally included. Five types of disinhibitory interventions were identified: focal ankle joint cooling (FAJC), manual therapy, fibular reposition taping (FRT), whole-body vibration (WBV), and transcranial direct current stimulation (tDCS). There were moderate effects of FAJC on spinal excitability in ankle muscles (g = 0.55, 95% CI = 0.03-1.08, p = 0.040 for the soleus and g = 0.54, 95% CI = 0.01-1.07, p = 0.046 for the fibularis longus). In contrast, manual therapy, FRT, WBV were not effective. Finally, 4 weeks of tDCS combined with eccentric exercise showed large effects on corticospinal excitability in 2 weeks after the intervention (g = 0.99, 95% CI = 0.14-1.85 for the fibularis longus and g = 1.02, 95% CI = 0.16-1.87 for the tibialis anterior). CONCLUSIONS FAJC and tDCS may be effective in counteracting AMI. However, the current evidence of mainly short-term studies to support the use of disinhibitory interventions is too limited to draw definitive conclusions.
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Affiliation(s)
- Kyung-Min Kim
- Department of Sport Science, Sungkyunkwan University, Suwon-si, Korea
- Department of Kinesiology and Sport Sciences, University of Miami, Coral Gables, FL, USA
| | - Alan R Needle
- Department of Public Health & Exercise Science, Appalachian State University, Boone, NC, USA
- Department of Rehabilitation Sciences, Appalachian State University, Boone, NC, USA
| | - Joo-Sung Kim
- Department of Kinesiology and Sport Sciences, University of Miami, Coral Gables, FL, USA
| | - Yong Woo An
- Department of Health and Human Sciences, Loyola Marymount University, Los Angeles, CA, USA
| | - David Cruz-Díaz
- Department of Health Sciences, Faculty of Health Sciences, University of Jaén, Jaén, Spain
| | - Wolfgang Taube
- Department of Neurosciences and Movement Sciences, University of Fribourg, Fribourg, Switzerland
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Yen CL, Petrie MA, Suneja M, Shields RK. Neuromuscular and gene signaling responses to passive whole-body heat stress in young adults. J Therm Biol 2023; 118:103730. [PMID: 37890230 DOI: 10.1016/j.jtherbio.2023.103730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 09/13/2023] [Accepted: 10/13/2023] [Indexed: 10/29/2023]
Abstract
This study aimed to investigate whether acute passive heat stress 1) decreases muscle Maximal Voluntary Contraction (MVC); 2) increases peripheral muscle fatigue; 3) increases spinal cord excitability, and 4) increases key skeletal muscle gene signaling pathways in skeletal muscle. Examining the biological and physiological markers underlying passive heat stress will assist us in understanding the potential therapeutic benefits. MVCs, muscle fatigue, spinal cord excitability, and gene signaling were examined after control or whole body heat stress in an environmental chamber (heat; 82 °C, 10% humidity for 30 min). Heart Rate (HR), an indicator of stress response, was correlated to muscle fatigue in the heat group (R = 0.59; p < 0.05) but was not correlated to MVC, twitch potentiation, and H reflex suppression. Sixty-one genes were differentially expressed after heat (41 genes >1.5-fold induced; 20 < 0.667 fold repressed). A strong correlation emerged between the session type (control or heat) and principal components (PC1) (R = 0.82; p < 0.005). Cell Signal Transduction, Metabolism, Gene Expression and Transcription, Immune System, DNA Repair, and Metabolism of Proteins were pathway domains with the largest number of genes regulated after acute whole body heat stress. Acute whole-body heat stress may offer a physiological stimulus for people with a limited capacity to exercise.
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Affiliation(s)
- Chu-Ling Yen
- School of Physical Therapy and Graduate Institute of Rehabilitation Science, College of Medicine, Chang Gung University, Taoyuan, Taiwan; Chang Gung Memorial Hospital, Neuroscience Research Center, Linkou, Taoyuan, Taiwan
| | - Michael A Petrie
- Department of Physical Therapy and Rehabilitation Science, Roy and Lucille Carver College of Medicine, The University of Iowa, Medical Education Building, Iowa City, IA, USA
| | - Manish Suneja
- Department of Internal Medicine, Roy and Lucille Carver College of Medicine, The University of Iowa, Iowa City, IA, USA
| | - Richard K Shields
- Department of Physical Therapy and Rehabilitation Science, Roy and Lucille Carver College of Medicine, The University of Iowa, Medical Education Building, Iowa City, IA, USA.
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Chung S, Rodriguez A, Alijanpour E, McCann RS. Effects of A Single Balance Training Session on Neural Excitability in Individuals With Chronic Ankle Instability. J Sport Rehabil 2023; 32:847-854. [PMID: 37558224 DOI: 10.1123/jsr.2023-0024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 05/03/2023] [Accepted: 06/08/2023] [Indexed: 08/11/2023]
Abstract
CONTEXT Individuals with chronic ankle instability (CAI) demonstrate reduced spinal reflex modulation and corticospinal excitability of the soleus, which may contribute to decreased balance performance. OBJECTIVE To determine the effects of a single session of balance training on Spinal-reflexive excitability modulation and corticospinal excitability in those with CAI. DESIGN Randomized controlled trials. SETTING Research laboratory. PARTICIPANTS Thirty participants with CAI were randomly assigned to the balance training (BAL) or control (CON) group. MAIN OUTCOME MEASURES Modulation of soleus spinal-reflexive excitability was measured by calculating relative change in normalized Hoffmann reflexes (ratio of the H-reflex to the M-wave) from prone to single-leg standing. Corticospinal excitability was assessed during single-leg stance using transcranial magnetic stimulation, outcomes of which included active motor threshold (AMT), motor evoked potential, and cortical silent period (CSP). Balance performance was measured with center of pressure velocity in anterior to posterior and medial to lateral directions. Separate 2 × 2 repeated-measures analyses of variance were employed to determine the effect of group (BAL and CON) and time (baseline and posttraining) on each dependent variable. RESULTS There were significant group by time interactions in the modulation of soleus spinal-reflexive excitability (F1,27 = 4.763, P = .04); CSP at 100% AMT (F1,27 = 4.727, P = .04); and CSP at 120% AMT (F1,27 = 16.057, P < .01). A large effect size suggests increased modulation of spinal-reflexive excitability (d = 0.81 [0.03 to 1.54]) of the soleus in BAL compared with CON at posttest, while CSP at 100% (d = 0.95 [0.17 to 1.70]) and 120% AMT (d = 1.10 [0.29 to 1.84]) was reduced in BAL when compared with CON at posttest. CONCLUSION After a single session of balance training, individuals with CAI initiated increases in spinal reflex modulation and corticospinal excitability of the soleus. Thus, individuals with CAI who undergo balance training exhibit positive neural adaptations that are linked to improvements in balance performance.
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Affiliation(s)
- Sunghoon Chung
- School of Rehabilitation Sciences, Old Dominion University, Norfolk, VA,USA
| | | | - Elham Alijanpour
- School of Rehabilitation Sciences, Old Dominion University, Norfolk, VA,USA
| | - Ryan S McCann
- School of Rehabilitation Sciences, Old Dominion University, Norfolk, VA,USA
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Melo ASC, Taylor JL, Ferreira R, Cunha B, Ascenção M, Fernandes M, Sousa V, Cruz EB, Vilas-Boas JP, Sousa ASP. Differences in Trapezius Muscle H-Reflex between Asymptomatic Subjects and Symptomatic Shoulder Pain Subjects. Sensors (Basel) 2023; 23:s23094217. [PMID: 37177422 PMCID: PMC10180810 DOI: 10.3390/s23094217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 04/12/2023] [Accepted: 04/20/2023] [Indexed: 05/15/2023]
Abstract
In chronic shoulder pain, adaptations in the nervous system such as in motoneuron excitability, could contribute to impairments in scapular muscles, perpetuation and recurrence of pain and reduced improvements during rehabilitation. The present cross-sectional study aims to compare trapezius neural excitability between symptomatic and asymptomatic subjects. In 12 participants with chronic shoulder pain (symptomatic group) and 12 without shoulder pain (asymptomatic group), the H reflex was evoked in all trapezius muscle parts, through C3/4 nerve stimulation, and the M-wave through accessory nerve stimulation. The current intensity to evoke the maximum H reflex, the latency and the maximum peak-to-peak amplitude of both the H reflex and M-wave, as well as the ratio between these two variables, were calculated. The percentage of responses was considered. Overall, M-waves were elicited in most participants, while the H reflex was elicited only in 58-75% or in 42-58% of the asymptomatic and symptomatic participants, respectively. A comparison between groups revealed that the symptomatic group presented a smaller maximum H reflex as a percentage of M-wave from upper trapezius and longer maximal H reflex latency from the lower trapezius (p < 0.05). Subjects with chronic shoulder pain present changes in trapezius H reflex parameters, highlighting the need to consider trapezius neuromuscular control in these individuals' rehabilitation.
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Affiliation(s)
- Ana S C Melo
- Center for Rehabilitation Research, ESS (Escola Superior de Saúde), Polytechnic of Porto, Rua Dr. António Bernardino de Almeida, 400, 4200-072 Porto, Portugal
- Research Centre in Physical Activity, Health and Leisure, Faculty of Sport, University of Porto, Rua Dr. Plácido Costa, 91, 4200-450 Porto, Portugal
- Porto Biomechanics Laboratory (LABIOMEP-UP), University of Porto, Rua Dr. Plácido Costa, 91, 4200-450 Porto, Portugal
- Center for Interdisciplinary Applied Research in Health, School of Health, Setubal Polytechnic Institute, Campus do IPS Estefanilha, 2914-503 Setubal, Portugal
| | - Janet L Taylor
- Centre for Human Performance, School of Medical and Health Sciences, Edith Cowan University, Perth, WA 6027, Australia
- Neuroscience Research Australia, Sydney, NSW 2031, Australia
| | - Ricardo Ferreira
- Center for Rehabilitation Research, ESS (Escola Superior de Saúde), Polytechnic of Porto, Rua Dr. António Bernardino de Almeida, 400, 4200-072 Porto, Portugal
| | - Bruno Cunha
- Center for Rehabilitation Research, ESS (Escola Superior de Saúde), Polytechnic of Porto, Rua Dr. António Bernardino de Almeida, 400, 4200-072 Porto, Portugal
| | - Manuel Ascenção
- Center for Rehabilitation Research, ESS (Escola Superior de Saúde), Polytechnic of Porto, Rua Dr. António Bernardino de Almeida, 400, 4200-072 Porto, Portugal
| | - Mathieu Fernandes
- Center for Rehabilitation Research, ESS (Escola Superior de Saúde), Polytechnic of Porto, Rua Dr. António Bernardino de Almeida, 400, 4200-072 Porto, Portugal
| | - Vítor Sousa
- Center for Rehabilitation Research, ESS (Escola Superior de Saúde), Polytechnic of Porto, Rua Dr. António Bernardino de Almeida, 400, 4200-072 Porto, Portugal
| | - Eduardo B Cruz
- Department of Physiotherapy, Escola Superior de Saúde, Instituto Politécnico de Setúbal, Campus do IPS Estefanilha, 2914-503 Setúbal, Portugal
- Comprehensive Health Research Center (CHRC), Universidade Nova de Lisboa, 1169-056 Lisboa, Portugal
| | - J Paulo Vilas-Boas
- Porto Biomechanics Laboratory (LABIOMEP-UP), University of Porto, Rua Dr. Plácido Costa, 91, 4200-450 Porto, Portugal
- Centre of Research, Education, Innovation and Intervention in Sport (CIFI2D), Faculty of Sport, University of Porto, Rua Dr. Plácido Costa, 91, 4200-450 Porto, Portugal
| | - Andreia S P Sousa
- Center for Rehabilitation Research, ESS (Escola Superior de Saúde), Polytechnic of Porto, Rua Dr. António Bernardino de Almeida, 400, 4200-072 Porto, Portugal
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Kim JS, Kim KM, Chang E, Jung HC, Lee JM, Needle AR. Conduction Velocity of Spinal Reflex in Patients with Acute Lateral Ankle Sprain. Healthcare (Basel) 2022; 10. [PMID: 36141406 DOI: 10.3390/healthcare10091794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 09/09/2022] [Accepted: 09/13/2022] [Indexed: 11/25/2022] Open
Abstract
Recent literature has highlighted altered spinal-reflex excitability following acute lateral ankle sprain (ALAS), yet there is little information on the conduction velocity of spinal reflex pathways (CV-SRP) in these patients. Therefore, we aimed to investigate the effects of ALAS on the CV-SRP. We employed a cross-sectional study with two groups: ALAS (n = 30) and healthy controls (n = 30). The CV-SRP of the soleus, fibularis longus, and tibialis anterior was assessed using the H-index method. As secondary outcomes, H-reflex and M-wave latencies were assessed as well as acute symptoms including ankle swelling, pain, and self-reported ankle function. Separate group-by-limb ANOVA with repeated measures revealed a significant interaction for soleus CV-SRP (p < 0.001) and H-reflex latency (p < 0.001), showing significant slower CV-SRP and longer H-reflex latency in the involved limb of the ALAS group compared with both limbs in the control group. However, there was no significant interaction or main effect in any other ankle muscles (p > 0.05). A further correlation analysis showed a significant relationship between CV-SRP and acute symptoms, including ankle swelling (r = −0.37, p = 0.048) and self-reported ankle function (r = 0.44, p = 0.017) in ALAS patients. These results suggest a disrupted functionality of the afferent pathway and/or synaptic transmission following ALAS. Level of Evidence: 4.
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Mustafa H, Harrison A, Sun Y, Pearcey GEP, Follmer B, Nazaroff BM, Rhodes RE, Zehr EP. Five weeks of Yuishinkai karate training improves balance and neuromuscular function in older adults: a preliminary study. BMC Sports Sci Med Rehabil 2022; 14:65. [PMID: 35410626 PMCID: PMC8997192 DOI: 10.1186/s13102-022-00458-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 03/30/2022] [Indexed: 12/03/2022]
Abstract
Background Martial arts training has shown positive impacts on balance and physiological measurements. Further investigation of the contents and feasibility of an effective therapeutic assessment of martial arts is needed in older adults, mainly for future applications and real-world implementation. Methods Sixteen older adults (8 male, 8 female, age 59–90 years), with or without chronic conditions, participated in a preliminary study using 5-weeks of karate training and a triple baseline control procedure. Group and single subject data analyses were conducted for dynamic balance, Timed Up and Go (TUG), hand grip, ankle plantarflexion force, and spinal cord excitability (via the soleus H-reflex) pre- and post-training. Results On average, participants completed a total of 2437 steps, 1762 turns, 3585 stance changes, 2047 punches, 2757 blocks, and 1253 strikes. Karate training improved dynamic balance performance such that the group average time was reduced (time to target (−13.6%, p = 0.020) and time to center (−8.3%, p = 0.010)). TUG was unchanged when considering the entire group (p = 0.779), but six participants displayed significant changes. Left handgrip (7.9%, p = 0.037), and plantarflexion force in the right (28.8%, p = 0.045) and left leg (13.3%, p = 0.024) increased for the group. Spinal cord excitability remained unchanged in group data analysis but 5 individuals had modulated Hmax/Mmax ratios. Conclusion 5-weeks of karate training delivered in a fashion to mimic generally accessible community-level programs improved balance and strength in older adults. Whole-body movement embodied in karate training enhanced neuromuscular function and postural control. We met the overriding goal of this preliminary study to emphasize and assess feasibility and safety for the generalizability of martial arts interventions to real-world communities to impact health outcomes. Further quantitative work should explore threshold dose and development of martial arts training interventions as potential “exercise is medicine” functional fitness for older adults.
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Affiliation(s)
- Hajer Mustafa
- Rehabilitation Neuroscience Laboratory, University of Victoria, Room 172, McKinnon Building, 3800 Finnerty Road, Victoria, BC, V8P 5C2, Canada.,School of Exercise Science, Physical and Health Education, University of Victoria, Victoria, BC, Canada.,Human Discovery Science, International Collaboration on Repair Discoveries (ICORD), Vancouver, BC, Canada
| | - Aimee Harrison
- Rehabilitation Neuroscience Laboratory, University of Victoria, Room 172, McKinnon Building, 3800 Finnerty Road, Victoria, BC, V8P 5C2, Canada.,School of Exercise Science, Physical and Health Education, University of Victoria, Victoria, BC, Canada.,Human Discovery Science, International Collaboration on Repair Discoveries (ICORD), Vancouver, BC, Canada.,Behavioural Medicine Laboratory, University of Victoria, Victoria, BC, Canada
| | - Yao Sun
- Rehabilitation Neuroscience Laboratory, University of Victoria, Room 172, McKinnon Building, 3800 Finnerty Road, Victoria, BC, V8P 5C2, Canada.,School of Exercise Science, Physical and Health Education, University of Victoria, Victoria, BC, Canada.,Human Discovery Science, International Collaboration on Repair Discoveries (ICORD), Vancouver, BC, Canada
| | - Gregory E P Pearcey
- Rehabilitation Neuroscience Laboratory, University of Victoria, Room 172, McKinnon Building, 3800 Finnerty Road, Victoria, BC, V8P 5C2, Canada.,Human Discovery Science, International Collaboration on Repair Discoveries (ICORD), Vancouver, BC, Canada.,Centre for Biomedical Research, University of Victoria, Victoria, BC, Canada
| | - Bruno Follmer
- Rehabilitation Neuroscience Laboratory, University of Victoria, Room 172, McKinnon Building, 3800 Finnerty Road, Victoria, BC, V8P 5C2, Canada.,School of Exercise Science, Physical and Health Education, University of Victoria, Victoria, BC, Canada.,Human Discovery Science, International Collaboration on Repair Discoveries (ICORD), Vancouver, BC, Canada
| | - Benjamin M Nazaroff
- Rehabilitation Neuroscience Laboratory, University of Victoria, Room 172, McKinnon Building, 3800 Finnerty Road, Victoria, BC, V8P 5C2, Canada.,School of Exercise Science, Physical and Health Education, University of Victoria, Victoria, BC, Canada.,Human Discovery Science, International Collaboration on Repair Discoveries (ICORD), Vancouver, BC, Canada
| | - Ryan E Rhodes
- School of Exercise Science, Physical and Health Education, University of Victoria, Victoria, BC, Canada.,Behavioural Medicine Laboratory, University of Victoria, Victoria, BC, Canada
| | - E Paul Zehr
- Rehabilitation Neuroscience Laboratory, University of Victoria, Room 172, McKinnon Building, 3800 Finnerty Road, Victoria, BC, V8P 5C2, Canada. .,School of Exercise Science, Physical and Health Education, University of Victoria, Victoria, BC, Canada. .,Human Discovery Science, International Collaboration on Repair Discoveries (ICORD), Vancouver, BC, Canada. .,Centre for Biomedical Research, University of Victoria, Victoria, BC, Canada. .,Division of Medical Sciences, University of Victoria, Victoria, BC, Canada.
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Cash JJ, van Werkhoven H, Cole KJ, Needle AR. The effects of 72 h of dynamic ankle immobilization on neural excitability and lower extremity kinematics. Gait Posture 2022; 93:198-204. [PMID: 35183836 DOI: 10.1016/j.gaitpost.2022.02.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 01/20/2022] [Accepted: 02/09/2022] [Indexed: 02/02/2023]
Abstract
BACKGROUND Ankle injuries can foster maladaptive changes in nervous system function that predisposes patients to subsequent injury. Patients are often placed in a dynamic boot immobilizer (BI) following injury; however, little is known about the effects of this treatment on neuromechanical function. RESEARCH QUESTION We aimed to determine the effect of 72 h of BI-use on neural excitability and lower extremity joint motion in a healthy cohort. METHODS Twelve uninjured individuals (20.8 ± 1.4 yrs, 1.7 ± 0.1 m, 75.2 ± 9.9 kg) participated in this crossover study. Neural excitability and lower extremity kinematics were assessed before and after 72 h of BI or compression sock (CS) use. Neural excitability was assessed via the Hoffmann (H) reflex and transcranial magnetic stimulation of the motor cortex by measuring muscle activation at the tibialis anterior, peroneus longus, and soleus of the immobilized extremity. Three-dimensional lower extremity joint angles were assessed while participants walked on a treadmill. Repeated-measures analyses of variance detected changes in neural excitability and peak joint angles across time-points and testing conditions, while statistical parametric mapping (SPM) was implemented to determine continuous joint angle changes (α = 0.05). RESULTS Pre-BI to post-BI, HMax:MMax ratio (F = 6.496; p = 0.031) significantly decreased. The BI did not alter resting motor threshold (F = 0.601; p = 0.468), or motor evoked potential amplitudes (F > 2.82; p > 0.608). Significant changes in peak knee and hip angles in the frontal and transverse planes were observed (p < 0.05), with no changes at the ankle. SPM analyses revealed significant hip and knee changes in range of motion (p < 0.05). SIGNIFICANCE Decreased measures of reflex but not corticospinal excitability suggest that BI-use for 72 h unloaded the joint enough to generate peripheral changes, but not the CNS, as has been described in casting models. Further, kinematic changes were observed in proximal lower extremity joints, likely due to swing-phase adaptations while wearing the BI.
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Affiliation(s)
- Jasmine J Cash
- Department of Health Sciences and Research, Medical University of South Carolina, Charleston, SC, USA.
| | - Herman van Werkhoven
- Department of Health and Exercise Science, Appalachian State University, Boone, NC, USA.
| | - Kelly J Cole
- Department of Health and Exercise Science, Appalachian State University, Boone, NC, USA.
| | - Alan R Needle
- Department of Health and Exercise Science, Appalachian State University, Boone, NC, USA.
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Abdulhadi IG, Al-Mahdawi AM, Hamdan FB. Electrophysiological findings in patients with restless legs syndrome. Sleep Med 2021; 87:151-157. [PMID: 34610569 DOI: 10.1016/j.sleep.2021.09.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 09/02/2021] [Accepted: 09/14/2021] [Indexed: 11/16/2022]
Abstract
BACKGROUND Restless legs syndrome (RLS) manifests as an urge to move the body to relieve the discomfortable sensations, primarily when resting, sitting, laying down, or sleeping. Diagnosis of RLS relies on clinical criteria, and the immobilization test was the only instrumental tool with equivocal results. OBJECTIVES To assess different electrophysiological findings in patients with RLS, and compare the diagnostic values of these parameters in the diagnosis of RLS. METHODS 30 patients with primary RLS and 30 controls who were matched for age and gender were studied. Participant's demographics, laboratory findings, and electrophysiological test, namely nerve conduction studies (NCS), cutaneous silent period (CSP), H reflex and sympathetic skin response (SSR), F-wave latency, amplitude, F-wave duration (FWD), and the ratio between FWD and duration of the corresponding compound muscle action potential (FWD/CMAPD) were analyzed. RESULTS None of the patients showed altered NCS data. FWD of upper (12.37 ± 2.77 ms) and lower limb (21.71 ± 5.24 ms) were significantly longer in patients. Also, FWD/CMAP duration of the upper (1.03 ± 0.2) and lower limb (2.02 ± 0.55) was longer in patients. Likewise, they exhibited delayed CSP latency from TA (110.62 ± 13.73 ms) and APB (77.35 ± 12.16 ms) whereas the CSP duration from TA and APB was decreased (37.36 ± 11.59 ms; 42.55 ± 7.97 ms, respectively). The SSR latency was not different, and right-sided H reflex amplitude (5.07 ± 3.98 mV) and H/M ratio (0.65 ± 1.81) were significantly increased in the patient group. CONCLUSION The data suggest that there may be a dysfunction of the inhibitory/excitatory circuits at a spinal level; and no pathology in the peripheral nerves. The unilateral difference of H reflex amplitude and H/M ratio may suggest asymmetrical central inhibitory dysfunction. Further prospective studies with larger cohorts are now needed to evaluate the pathophysiology of RLS with different neurophysiological assessment tools.
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Affiliation(s)
| | | | - Farqad Bader Hamdan
- Department of Physiology, College of Medicine, Al-Nahrain University, Baghdad, Iraq.
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Delgado‐Lezama R, Bravo‐Hernández M, Franco‐Enzástiga Ú, De la Luz‐Cuellar YE, Alvarado‐Cervantes NS, Raya‐Tafolla G, Martínez‐Zaldivar LA, Vargas‐Parada A, Rodríguez‐Palma EJ, Vidal‐Cantú GC, Guzmán‐Priego CG, Torres‐López JE, Murbartián J, Felix R, Granados‐Soto V. The role of spinal cord extrasynaptic α 5 GABA A receptors in chronic pain. Physiol Rep 2021; 9:e14984. [PMID: 34409771 PMCID: PMC8374381 DOI: 10.14814/phy2.14984] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Revised: 06/25/2021] [Accepted: 06/29/2021] [Indexed: 11/24/2022] Open
Abstract
Chronic pain is an incapacitating condition that affects a large population worldwide. Until now, there is no drug treatment to relieve it. The impairment of GABAergic inhibition mediated by GABAA receptors (GABAA R) is considered a relevant factor in mediating chronic pain. Even though both synaptic and extrasynaptic GABAA inhibition are present in neurons that process nociceptive information, the latter is not considered relevant as a target for the development of pain treatments. In particular, the extrasynaptic α5 GABAA Rs are expressed in laminae I-II of the spinal cord neurons, sensory neurons, and motoneurons. In this review, we discuss evidence showing that blockade of the extrasynaptic α5 GABAA Rs reduces mechanical allodynia in various models of chronic pain and restores the associated loss of rate-dependent depression of the Hoffmann reflex. Furthermore, in healthy animals, extrasynaptic α5 GABAA R blockade induces both allodynia and hyperalgesia. These results indicate that this receptor may have an antinociceptive and pronociceptive role in healthy and chronic pain-affected animals, respectively. We propose a hypothesis to explain the relevant role of the extrasynaptic α5 GABAA Rs in the processing of nociceptive information. The data discussed here strongly suggest that this receptor could be a valid pharmacological target to treat chronic pain states.
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Affiliation(s)
| | - Mariana Bravo‐Hernández
- Neuroregeneration LaboratoryDepartment of AnesthesiologyUniversity of CaliforniaSan Diego, La JollaCAUSA
| | | | | | | | | | | | | | | | | | - Crystell G. Guzmán‐Priego
- Mechanisms of Pain LaboratoryDivisión Académica de Ciencias de la SaludUniversidad Juárez Autónoma de Tabasco, VillahermosaTabascoMexico
| | - Jorge E. Torres‐López
- Mechanisms of Pain LaboratoryDivisión Académica de Ciencias de la SaludUniversidad Juárez Autónoma de Tabasco, VillahermosaTabascoMexico
- Hospital Regional de Alta Especialidad “Dr. Juan Graham Casasús”, VillahermosaTabascoMexico
| | | | - Ricardo Felix
- Departamento de Biología CelularCinvestavMexico CityMexico
| | - Vinicio Granados‐Soto
- Neurobiology of Pain LaboratoryDepartamento de FarmacobiologíaCinvestavMexico CityMexico
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Funaba M, Imajo Y, Suzuki H, Nishida N, Nagao Y, Sakamoto T, Fujimoto K, Sakai T. The associations between radiological and neurological findings of degenerative cervical myelopathy: radiological analysis based on kinematic CT myelography and evoked potentials of the spinal cord. J Neurosurg Spine 2021:1-12. [PMID: 34243153 DOI: 10.3171/2020.11.spine201626] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 11/23/2020] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Neurological and imaging findings play significant roles in the diagnosis of degenerative cervical myelopathy (DCM). Consistency between neurological and imaging findings is important for diagnosing DCM. The reasons why neurological findings exhibit varying sensitivity for DCM and their associations with radiological findings are unclear. This study aimed to identify associations between radiological parameters and neurological findings in DCM and elucidate the utility of concordance between imaging and neurological findings for diagnosing DCM. METHODS One hundred twenty-one patients with DCM were enrolled. The Japanese Orthopaedic Association (JOA) score, radiological parameters, MRI and kinematic CT myelography (CTM) parameters, and the affected spinal level (according to multimodal spinal cord evoked potential examinations) were assessed. Kinematic CTM was conducted with neutral positioning or at maximal extension or flexion of the cervical spine. The cross-sectional area (CSA) of the spinal cord, dynamic change in the CSA, C2-7 range of motion, and C2-7 angle were measured. The associations between radiological parameters and hyperreflexia, the Hoffmann reflex, the Babinski sign, and positional sense were analyzed via multiple logistic regression analysis. RESULTS In univariate analyses, the upper- and lower-limb JOA scores were found to be significantly associated with a positive Hoffmann reflex and a positive Babinski sign, respectively. In the multivariate analysis, a positive Hoffmann reflex was associated with a higher MRI grade (p = 0.026, OR 2.23) and a responsible level other than C6-7 (p = 0.0017, OR 0.061). A small CSA during flexion was found to be significantly associated with a positive Babinski sign (p = 0.021, OR 0.90). The presence of ossification of the posterior longitudinal ligament (p = 0.0045, OR 0.31) and a larger C2-7 angle during flexion (p = 0.01, OR 0.89) were significantly associated with abnormal great toe proprioception (GTP). CONCLUSIONS This study found that the Hoffmann reflex is associated with chronic and severe spinal cord compression but not the dynamic factors. The Babinski sign is associated with severe spinal cord compression during neck flexion. The GTP is associated with large cervical lordosis. These imaging features can help us understand the characteristics of the neurological findings.
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Harmsen JF, Latella C, Mesquita R, Fasse A, Schumann M, Behringer M, Taylor J, Nosaka K. H-reflex and M-wave responses after voluntary and electrically evoked muscle cramping. Eur J Appl Physiol 2020; 121:659-672. [PMID: 33245422 DOI: 10.1007/s00421-020-04560-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 11/10/2020] [Indexed: 11/28/2022]
Abstract
PURPOSE Despite the widespread occurrence of muscle cramps, their underlying neurophysiological mechanisms remain unknown. To better understand the etiology of muscle cramps, this study investigated acute effects of muscle cramping induced by maximal voluntary isometric contractions (MVIC) and neuromuscular electrical stimulation (NMES) on the amplitude of Hoffmann reflexes (H-reflex) and compound muscle action potentials (M-wave). METHODS Healthy men (n = 14) and women (n = 3) participated in two identical sessions separated by 7 days. Calf muscle cramping was induced by performing MVIC of the plantar flexors in a prone position followed by 2.5-s NMES over the plantar flexors with increasing frequency and intensity. H-reflexes and M-waves evoked by tibial nerve stimulation in gastrocnemius medialis (GM) and soleus were recorded at baseline, and after MVIC-induced cramps and the NMES protocol. RESULTS Six participants cramped after MVIC, and H-reflex amplitude decreased in GM and soleus in Session 1 (- 33 ± 32%, - 34 ± 33%, p = 0.031) with a similar trend in Session 2 (5 cramped, p = 0.063), whereas the maximum M-wave was unchanged. After NMES, 11 (Session 1) and 9 (Session 2) participants cramped. H-reflex and M-wave recruitment curves shifted to the left in both sessions and muscles after NMES independent of cramping (p ≤ 0.001). CONCLUSION Changes in H-reflexes after a muscle cramp induced by MVIC and NMES were inconsistent. While MVIC-induced muscle cramps reduced H-reflex amplitude, muscle stretch to end cramping was a potential contributing factor. By contrast, NMES may potentiate H-reflexes and obscure cramp-related changes. Thus, the challenge for future studies is to separate the neural consequences of cramping from methodology-based effects.
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Affiliation(s)
- Jan-Frieder Harmsen
- Department of Molecular and Cellular Sports Medicine, German Sport University Cologne, Am Sportpark Müngersdorf 6, 50933, Cologne, Germany.
- Department of Nutrition and Movement Sciences, School for Nutrition and Translational Research in Metabolism, Maastricht University Medical Center, Maastricht, The Netherlands.
| | - Christopher Latella
- Center for Exercise and Sports Science Research, School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia
- Neurophysiology Research Laboratory, Edith Cowan University, Joondalup, WA, Australia
| | - Ricardo Mesquita
- Center for Exercise and Sports Science Research, School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia
| | | | - Moritz Schumann
- Department of Molecular and Cellular Sports Medicine, German Sport University Cologne, Am Sportpark Müngersdorf 6, 50933, Cologne, Germany
| | - Michael Behringer
- Faculty of Sport Sciences, Goethe University Frankfurt, Frankfurt, Germany
| | - Janet Taylor
- Center for Exercise and Sports Science Research, School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia
- Neurophysiology Research Laboratory, Edith Cowan University, Joondalup, WA, Australia
| | - Kazunori Nosaka
- Center for Exercise and Sports Science Research, School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia
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Yurttutmuş Z, Ekici Zincirci D, Bardak AN, Topkara B, Aydın T, Karacan I, Türker KS. A stimulus rate that is not influenced by homosynaptic post-activation depression in chronic stroke. Somatosens Mot Res 2020; 37:271-276. [PMID: 32811248 DOI: 10.1080/08990220.2020.1807925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
PURPOSE To determine a stimulus rate that is not influenced by homosynaptic post-activation depression for H-reflex studies in patients with chronic spasticity. MATERIALS AND METHODS A cohort of 15 chronic stroke patients with soleus spasticity who received inpatient treatment at our rehabilitation centre participated in this study. The effect of stimulus frequency related depression on H-reflex size was tested using four different stimulus rates (0.1, 0.2, 0.3 and 1 Hz). The affected sides stibial nerve was stimulated by a bipolar electrode. The H-reflex was recorded from the affected sideed sidee sidehe affected smine stimulus frequency related depression of H-reflex size, amplitude of the first H-reflex response (H1) was used as control and amplitude of the second H-reflex response (H2) as test. RESULTS H2 amplitude for frequency of 1 Hz, 0.3 Hz, 0.2 Hz and 0.1 Hz were 74.3, 84.1, 85.5 and 92.7% of H1, respectively. Depression of H2 amplitude was statistically significant for 1 Hz, 0.3 Hz and 0.2 Hz (p < 0.001, p = 0.002, p = 0.024, respectively). CONCLUSIONS Higher frequency stimulation of Ia afferents than 0.1 Hz induced a stimulus frequency-related depression of H-reflex size in patients with chronic spasticity. The optimal stimulus rate for H-reflex was found to be 0.1 Hz.
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Affiliation(s)
- Zeynep Yurttutmuş
- Istanbul Physical Therapy Rehabilitation Training and Research Hospital, Istanbul, Turkey
| | - Dilara Ekici Zincirci
- Istanbul Physical Therapy Rehabilitation Training and Research Hospital, Istanbul, Turkey
| | - Ayse Nur Bardak
- Istanbul Physical Therapy Rehabilitation Training and Research Hospital, Istanbul, Turkey
| | - Betilay Topkara
- Physiology Department, Koç University School of Medicine, Istanbul, Turkey
| | - Tugba Aydın
- Istanbul Physical Therapy Rehabilitation Training and Research Hospital, Istanbul, Turkey
| | - Ilhan Karacan
- Istanbul Physical Therapy Rehabilitation Training and Research Hospital, Istanbul, Turkey
| | - Kemal S Türker
- Physiology Department, Koç University School of Medicine, Istanbul, Turkey
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Baudry S, Duchateau J. Aftereffects of prolonged Achilles tendon vibration on postural control are reduced in older adults. Exp Gerontol 2020; 131:110822. [PMID: 31899339 DOI: 10.1016/j.exger.2019.110822] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 12/21/2019] [Accepted: 12/26/2019] [Indexed: 11/16/2022]
Abstract
AIM To assess the change in the contribution of proprioceptive signal from leg muscles in postural control with ageing. METHODS Fifteen young (~23 yr) and fifteen older adults (~68 yr) participated in Experiment 1, which consisted of recording the mean position of the centre of pressure (CoP), CoP path length, CoP velocity, and the amplitude of the Hoffmann (H) reflex and maximal M wave (MMAX) in the soleus muscle during upright standing, before and after 1 h of bilateral Achilles tendon vibration applied in seated posture. Eight young (~24 yr) and eight older adults (~67 yr) participated in Experiment 2 consisting of recording H-reflex and MMAX in seated posture before and after the 1-h vibration procedure used in Experiment 1. RESULTS Immediately after the 1-h vibration, the mean CoP position shifted forward in both groups (p < 0.05), with a greater magnitude of change (% pre-vibration) in young [mean(SD); 74(41)%] than older adults [44(40)%; p < 0.05]. The CoP path length and velocity only increased in young adults after vibration (p < 0.05). The H-reflex amplitude decreased only in young adults after vibration [before: 35(12); after: 16(13)% Mmax, p < 0.05] during upright standing (Experiment 1), whereas it decreased similarly (p > 0.05) in young [before: 47(12)% Mmax; after: 28(17)% Mmax] and older adults [before: 34(13)% Mmax; after: 21(14)% Mmax] in seated posture (Experiment 2). CONCLUSION Prolonged Achilles tendon vibrations lead to lesser postural perturbation in older than in young adults, supporting the assumption of a decreased reliance on leg muscle proprioception in postural control with ageing.
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Affiliation(s)
- Stéphane Baudry
- Laboratory of Applied Biology, Research Unit in Applied Neurophysiology, ULB-Neurosciences Institute (UNI), Université Libre de Bruxelles (ULB), 808 route de Lennik, 1070 Brussels, Belgium.
| | - Jacques Duchateau
- Laboratory of Applied Biology, Research Unit in Applied Neurophysiology, ULB-Neurosciences Institute (UNI), Université Libre de Bruxelles (ULB), 808 route de Lennik, 1070 Brussels, Belgium
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Otzel DM, Hass CJ, Wikstrom EA, Bishop MD, Borsa PA, Tillman MD. Motoneuron Function Does not Change Following Whole-Body Vibration in Individuals With Chronic Ankle Instability. J Sport Rehabil 2019; 28:614-22. [PMID: 30222478 DOI: 10.1123/jsr.2017-0364] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 07/20/2018] [Accepted: 07/22/2018] [Indexed: 11/18/2022]
Abstract
CONTEXT Following a lateral ankle sprain, ∼40% of individuals develop chronic ankle instability (CAI), characterized by recurrent injury and sensations of giving way. Deafferentation due to mechanoreceptor damage postinjury is suggested to contribute to arthrogenic muscle inhibition (AMI). Whole-body vibration (WBV) has the potential to address the neurophysiologic deficits accompanied by CAI and, therefore, possibly prevent reinjury. OBJECTIVE To determine if an acute bout of WBV can improve AMI and proprioception in individuals with CAI. DESIGN AND PARTICIPANTS The authors examined if an acute bout of WBV can improve AMI and proprioception in individuals with CAI with a repeated-measures design. A total of 10 young adults with CAI and 10 age-matched healthy controls underwent a control, sham, and WBV condition in randomized order. SETTING Biomechanics laboratory. INTERVENTION WBV. MAIN OUTCOME MEASURES Motoneuron pool recruitment was assessed via Hoffmann reflex (H-reflex) in the soleus. Proprioception was evaluated using ankle joint position sense at 15° and 20° of inversion. Both were assessed prior to, immediately following, and 30 minutes after the intervention (pretest, posttest, and 30mPost, respectively). RESULTS Soleus maximum H-reflex:M-response (H:M) ratios were 25% lower in the CAI group compared with the control group (P = .03). Joint position sense mean constant error did not differ between groups (P = .45). Error at 15° in the CAI (pretest 0.8 [1.6], posttest 2.0 [2.8], 30mPost 2.0 [1.9]) and control group (pretest 0.8 [2.0], posttest 0.6 [2.9], 30mPost 0.5 [2.1]) did not improve post-WBV. Error at 20° did not change post-WBV in the CAI (pretest 1.3 [1.7], posttest 1.0 [2.4], 30mPost 1.5 [2.2]) or control group (pretest -0.3 [3.0], posttest 0.8 [2.1], 30mPost 0.6 [1.8]). CONCLUSION AMI is present in the involved limb of individuals with CAI. The acute response following a single bout of WBV did not ameliorate the presence of AMI nor improve proprioception in those with CAI.
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Kim KM, Kim JS, Cruz-Díaz D, Ryu S, Kang M, Taube W. Changes in Spinal and Corticospinal Excitability in Patients with Chronic Ankle Instability: A Systematic Review with Meta-Analysis. J Clin Med 2019; 8:E1037. [PMID: 31315231 DOI: 10.3390/jcm8071037] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 07/10/2019] [Accepted: 07/10/2019] [Indexed: 12/26/2022] Open
Abstract
The objective of this systematic review with meta-analysis was to determine alterations in spinal and corticospinal excitability of ankle muscles in patients with chronic ankle instability (CAI) compared to uninjured controls. Independent researchers performed comprehensive literature searches of electronic databases and included studies that compared groups with and without CAI and investigated neural excitability with Hoffmann reflex (H-reflex) and/or transcranial magnetic stimulation (TMS). A fixed-effect meta-analysis was conducted to determine group differences for (1) soleus and fibularis maximal H-reflex (Hmax)/maximal M-wave (Mmax)-ratios, and (2) soleus and fibularis longus cortical motor thresholds (CMTs). Seventeen studies were included in the current meta-analysis. They showed that the Hmax/Mmax-ratios of the soleus and the fibularis longus in the CAI group were significantly lower than those in the uninjured control group (soleus: d = −0.41, p < 0.001; fibularis longus: d = −0.27, p = 0.04). There was no evidence for changes in the CMT. This systematic review is the first to demonstrate evidence that patients with CAI present decreased spinal reflex excitability in the soleus and fibularis longus. However, there is no evidence of changes in supraspinal excitability when considering only the CMT. The latter result needs to be interpreted with caution as all except one study demonstrate some changes at the supraspinal level with CAI.
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17
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Pearcey GEP, Zehr EP. Exploiting cervicolumbar connections enhances short-term spinal cord plasticity induced by rhythmic movement. Exp Brain Res 2019; 237:2319-29. [PMID: 31286172 DOI: 10.1007/s00221-019-05598-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 07/04/2019] [Indexed: 01/08/2023]
Abstract
Arm cycling causes suppression of soleus (SOL) Hoffmann (H-) reflex that outlasts the activity period. Arm cycling presumably activates propriospinal networks that modulate Ia presynaptic inhibition. Interlimb pathways are thought to relate to the control of quadrupedal locomotion, allowing for smooth, coordinated movement of the arms and legs. We examined whether the number of active limb pairs affects the amount and duration of activity-dependent plasticity of the SOL H-reflex. On separate days, 14 participants completed 4 randomly ordered 30 min experimental sessions: (1) quiet sitting (CTRL); (2) arm cycling (ARM); (3) leg cycling (LEG); and (4) arm and leg cycling (A&L) on an ergometer. SOL H-reflex and M-wave were evoked via electrical stimulation of the tibial nerve. M-wave and H-reflex recruitment curves were recorded, while the participants sat quietly prior to, 10 and 20 min into, immediately after, and at 2.5, 5, 7.5, 10, 15, 20, 25, and 30 min after each experimental session. Normalized maximal H-reflexes were unchanged in CTRL, but were suppressed by > 30% during the ARM, LEG, and A&L. H-reflex suppression outlasted activity duration for ARM (≤ 2.5 mins), LEG (≤ 5 mins), and A&L (≤ 30 mins). The duration of reflex suppression after A&L was greater than the algebraic summation of ARM and LEG. This non-linear summation suggests that using the arms and legs simultaneously-as in typical locomotor synergies-amplifies networks responsible for the short-term plasticity of lumbar spinal cord excitability. Enhanced activity of spinal networks may have important implications for the implementation of locomotor training for targeted rehabilitation.
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Pamukoff DN, Pietrosimone B, Lewek MD, Ryan ED, Weinhold PS, Lee DR, Blackburn JT. Immediate effect of vibratory stimuli on quadriceps function in healthy adults. Muscle Nerve 2017; 54:469-78. [PMID: 26872828 DOI: 10.1002/mus.25081] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 02/02/2016] [Accepted: 02/10/2016] [Indexed: 12/28/2022]
Abstract
INTRODUCTION The purpose of this study was to compare the effect of whole body vibration (WBV) and local muscle vibration (LMV) on quadriceps function. METHODS Sixty adults were randomized to WBV, LMV, or control groups. Quadriceps function [Hoffmann (H)-reflex, active motor threshold (AMT), motor evoked potential (MEP) and electromyographic amplitude, peak torque (PT), rate of torque development (RTD), and central activation ratio (CAR)] was assessed before and immediately after and 10 and 20 minutes after interventions. RESULTS WBV improved PT, CAR, AMT, EMG, and MEP amplitude, and EMG amplitude and CAR were greater than control after application. LMV improved EMG amplitude and AMT, and EMG amplitude was greater than control after application. AMT remained lower 10 and 20 minutes after WBV and LMV. No differences were noted between LMV and WBV. Vibration did not influence H-reflex or RTD. CONCLUSIONS WBV and LMV increased quadriceps function and may be used to enhance the efficacy of strengthening protocols. Muscle Nerve 54: 469-478, 2016.
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Affiliation(s)
- Derek N Pamukoff
- Department of Kinesiology, California State University, Fullerton, 800 North State College Boulevard, Fullerton, California, 92831, USA.,Department of Exercise and Sport Science, California State University, Fullerton, Fullerton, California, USA.,Curriculum in Human Movement Science, California State University, Fullerton, Fullerton, California, USA
| | - Brian Pietrosimone
- Department of Exercise and Sport Science, California State University, Fullerton, Fullerton, California, USA.,Curriculum in Human Movement Science, California State University, Fullerton, Fullerton, California, USA
| | - Michael D Lewek
- Department of Exercise and Sport Science, California State University, Fullerton, Fullerton, California, USA.,Curriculum in Human Movement Science, California State University, Fullerton, Fullerton, California, USA.,Division of Physical Therapy, Department of Allied Health Sciences, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Eric D Ryan
- Department of Exercise and Sport Science, California State University, Fullerton, Fullerton, California, USA.,Curriculum in Human Movement Science, California State University, Fullerton, Fullerton, California, USA
| | - Paul S Weinhold
- Curriculum in Human Movement Science, California State University, Fullerton, Fullerton, California, USA.,Department of Orthopedics, California State University, Fullerton, Fullerton, California, USA.,Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Chapel Hill, North Carolina, USA
| | - Dustin R Lee
- Department of Exercise and Sport Science, California State University, Fullerton, Fullerton, California, USA
| | - J Troy Blackburn
- Department of Exercise and Sport Science, California State University, Fullerton, Fullerton, California, USA.,Curriculum in Human Movement Science, California State University, Fullerton, Fullerton, California, USA.,Department of Orthopedics, California State University, Fullerton, Fullerton, California, USA
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Cattagni T, Merlet AN, Cornu C, Jubeau M. H-reflex and M-wave recordings: effect of pressure application to the stimulation electrode on the assessment of evoked potentials and subject's discomfort. Clin Physiol Funct Imaging 2017; 38:416-424. [PMID: 28444940 DOI: 10.1111/cpf.12431] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Accepted: 03/03/2017] [Indexed: 11/26/2022]
Abstract
This study aimed to compare the effect of different types of pressure applied to the stimulation electrode on assessing the efficiency of Ia-α-motoneuron transmission of the soleus muscle and the associated discomfort using electrical nerve stimulation. Twelve healthy young adults participated in three experimental sessions (one for each knee angle). The amplitudes of the maximal Hoffmann reflex (Hmax ) and motor potential (Mmax ) were recorded from the soleus muscle at 0°, 30° and 90° knee angles (0° full extension) through three pressure applications to the stimulation electrode: no pressure, pressure with manual application and pressure using adhesive tape. The soleus Hmax /Mmax were calculated to assess the efficiency of Ia-α-motoneuron transmission during varied knee angles and pressure application to the stimulation electrode. At the stimulation intensity evoking soleus Hmax and Mmax , subjects were asked to orally provide a value between 'no discomfort' (0) and 'worst possible discomfort' (10). The application of pressure on the stimulation electrode, particularly using adhesive tape, decreased both the stimulation intensity needed to evoke an electrophysiological response and the associated self-reported discomfort (P<0·05), while the Hmax /Mmax remained constant. At the stimulation intensity evoking Mmax , the electrical stimulation appeared to be more painful at 0° knee angle compared with 30° and 90° angles (P<0·01). To conclude, this study showed that a knee flexion and a pressure application to the stimulation electrode, especially using tape pressure, are recommended in the objective to reduce the patient/subjects' discomfort when eliciting evoked potentials on soleus muscle.
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Affiliation(s)
- Thomas Cattagni
- Laboratory "Movement, Interactions, Performance" (EA 4334), Faculty of Sport Sciences, University of Nantes, Nantes, France
| | - Angèle N Merlet
- Laboratory "Movement, Interactions, Performance" (EA 4334), Faculty of Sport Sciences, University of Nantes, Nantes, France
| | - Christophe Cornu
- Laboratory "Movement, Interactions, Performance" (EA 4334), Faculty of Sport Sciences, University of Nantes, Nantes, France
| | - Marc Jubeau
- Laboratory "Movement, Interactions, Performance" (EA 4334), Faculty of Sport Sciences, University of Nantes, Nantes, France
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Abstract
We aimed to investigate changes in electrophysiological findings in Turkish patients with restless legs syndrome (RLS), including F-wave latency (FWL), peripheral silent period (PSP), and Hoffmann reflex. The study took place in a university hospital in Turkey and involved 30 newly diagnosed RLS patients and 30 healthy controls who were matched for age and gender. Participant's demographics (age, gender, weight, and height), laboratory findings, and electrophysiological test outcomes were gathered and analyzed. There was no significant difference in the FWL of the median and ulnar nerves, whereas the H-wave maximum amplitude and H/M ratio were significantly higher in the RLS patients than in the controls at rest. All of the PSP parameters were similar between patients and controls for the abductor pollicis brevis and gastrocnemius muscles. However, for the tibialis anterior muscle, all the PSP duration parameters were shorter in the RLS patients, whereas the PSP latency parameters were similar. The data suggest that there may be a reduction in spinal segmental inhibition at the L4-L5-S1 level, but the mechanisms of inhibition at the L4-L5 and S1 levels may be different; furthermore, there may be no pathology in the peripheral nerves. Further prospective studies with larger cohorts are now needed to evaluate the pathophysiology of RLS with different neurophysiological assessment tools.
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Kim KM, Davis B, Hertel J, Hart J. Effects of Kinesio taping in patients with quadriceps inhibition: A randomized, single-blinded study. Phys Ther Sport 2016; 24:67-73. [PMID: 28126423 DOI: 10.1016/j.ptsp.2016.08.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Revised: 05/11/2016] [Accepted: 08/20/2016] [Indexed: 10/21/2022]
Abstract
OBJECTIVE To determine effects of Kinesio taping (KT) on quadriceps activation and maximal voluntary isometric contraction (MVIC) in patients with quadriceps inhibition. DESIGN Randomized, single-blinded. SETTING Laboratory. PATIENTS Sixteen participants (9 males, 7 females) with quadriceps inhibition, as determined by 90% or lower in central activation ratio (CAR), participated. MAIN OUTCOME MEASURES Hoffmann reflex (H-reflex) of the vastus medialis and quadriceps CAR and MVIC were measured before taping, and participants were randomly allocated to either KT (KT application with tension) or sham (non-elastic tape application without tension) group. H-reflexes were assessed immediately and 20 min after tape was applied over the rectus femoris. All outcomes were measured again after tape was removed when participants returned the laboratory 24-48 h after taping. RESULTS Two-way repeated ANOVA found no group-by-time interaction for: H-reflex (F3,42 = 1.94, P = 0.14), CAR (F1,14 = 0.03, P = 0.86), or MVIC (F1,14 = 0.007, P = 0.93). None of the outcome measures differed between groups or over time (P > 0.05). CONCLUSIONS KT applied to the rectus femoris did not change H-reflex of the vastus medialis and quadriceps CAR and MVIC in patients with quadriceps inhibition.
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Affiliation(s)
- Kyung-Min Kim
- University of Miami, 1507 Levante Avenue, Miami, FL 33146, USA.
| | - Brandon Davis
- Hampden-Sydney College, 80 College Road Hampden Sydney, VA 23943, USA.
| | - Jay Hertel
- University of Virginia, 210 Emmet St. South, PO Box 400407, Charlottesville, VA 22904, USA.
| | - Joseph Hart
- University of Virginia, 210 Emmet St. South, PO Box 400407, Charlottesville, VA 22904, USA.
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Larsen LE, Jakobsen LA, Jensen A, Lambden BM, Sørensen MR, Ellrich J. Inhibition of soleus Hoffmann reflex by ankle-foot orthosis application in healthy volunteers. Prosthet Orthot Int 2015; 39:444-53. [PMID: 24898556 DOI: 10.1177/0309364614535621] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Accepted: 04/21/2014] [Indexed: 02/03/2023]
Abstract
BACKGROUND An ankle-foot orthosis is suggested to actively assist dorsiflexion of the foot by induction of a positive proprioceptive impact to ankle dorsiflexor muscles. However, an objective proof is missing. OBJECTIVES To assess the proprioceptive impact of an ankle-foot orthosis application by Hoffmann reflex recordings of the soleus muscle under static conditions. It was hypothesized that the use of an ankle-foot orthosis facilitated dorsiflexor motor function and thus a decreased the soleus Hoffmann reflex. STUDY DESIGN Experimental study in healthy volunteers, pre-post test design. METHODS In all, 20 healthy volunteers were enrolled in order to assess the proprioceptive impact of orthosis application. The Hoffmann reflex was recorded before, during, and after orthosis application. RESULTS Under orthosis application, the Hoffmann reflex significantly decreased as compared to before (p < 0.05) and after application (p < 0.05). CONCLUSIONS Findings indicate an inhibition of plantarflexors probably induced by facilitation of ankle dorsiflexors under static conditions. At first glance, it seems that foot orthoses primarily have a stabilizing effect on ankle joints in terms of simple mechanical bandages. However, the present results suggest an additional active impact on proprioceptive control. CLINICAL RELEVANCE The putative neuromodulatory effect on motor control may support the application of such ankle-foot orthoses in, for example, drop foot. Furthermore, the objective assessment of a neurophysiological mode of action of orthoses by Hoffmann reflex recordings might be an appropriate primary outcome parameter in clinical trials.
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Affiliation(s)
- Lars E Larsen
- Laboratory for Clinical and Experimental Neurophysiology, Department of Neurology, Ghent University Hospital, Ghent, Belgium
| | - Lydia A Jakobsen
- Department of Health Science and Technology, Medical Faculty, Aalborg University, Aalborg, Denmark
| | - Anne Jensen
- Department of Health Science and Technology, Medical Faculty, Aalborg University, Aalborg, Denmark
| | | | - Morten R Sørensen
- Department of Health Science and Technology, Medical Faculty, Aalborg University, Aalborg, Denmark
| | - Jens Ellrich
- Department of Health Science and Technology, Medical Faculty, Aalborg University, Aalborg, Denmark
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23
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Abstract
CONTEXT Neuromuscular dysfunction of the leg and thigh musculature, including decreased strength and postural control, is common in patients with chronic ankle instability (CAI). Understanding how CAI affects specific neural pathways may provide valuable information for targeted therapies. OBJECTIVE To investigate differences in spinal reflexive and corticospinal excitability of the fibularis longus and vastus medialis between limbs in patients with unilateral CAI and between CAI patients and participants serving as healthy controls. DESIGN Case-control study. SETTING Research laboratory. PATIENTS OR OTHER PARTICIPANTS A total of 56 participants volunteered, and complete data for 21 CAI patients (9 men, 12 women; age = 20.81 ± 1.63 years, height = 171.57 ± 11.44 cm, mass = 68.84 ± 11.93 kg) and 24 healthy participants serving as controls (7 men, 17 women; age = 22.54 ± 2.92 years, height = 172.35 ± 10.85 cm, mass = 69.15 ± 12.30 kg) were included in the final analyses. Control participants were matched to CAI patients on sex, age, and limb dominance. We assigned "involved" limbs, which corresponded with the involved limbs of the CAI patients, to control participants. MAIN OUTCOME MEASURE(S) Spinal reflexive excitability was assessed via the Hoffmann reflex and normalized to a maximal muscle response. Corticospinal excitability was assessed using transcranial magnetic stimulation. Active motor threshold (AMT) was defined as the lowest transcranial magnetic stimulation intensity required to elicit motor-evoked potentials equal to or greater than 100 μV in 5 of 10 consecutive stimuli. We obtained motor-evoked potentials (MEPs) at percentages ranging from 100% to 140% of AMT. RESULTS Fibularis longus MEP amplitudes were greater in control participants than in CAI patients bilaterally at 100% AMT (control involved limb: 0.023 ± 0.031; CAI involved limb: 0.014 ± 0.008; control uninvolved limb: 0.021 ± 0.022; CAI uninvolved limb: 0.015 ± 0.007; F1,41 = 4.551, P = .04) and 105% AMT (control involved limb: 0.029 ± 0.026; CAI involved limb: 0.021 ± 0.009; control uninvolved limb: 0.034 ± 0.037; CAI uninvolved limb: 0.023 ± 0.013; F1,35 = 4.782, P = .04). We observed no differences in fibularis longus MEP amplitudes greater than 110% AMT and no differences in vastus medialis corticospinal excitability (P > .05). We noted no differences in the Hoffmann reflex between groups for the vastus medialis (F1,37 = 0.103, P = .75) or the fibularis longus (F1,41 = 1.139, P = .29). CONCLUSIONS Fibularis longus corticospinal excitability was greater in control participants than in CAI patients.
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Affiliation(s)
| | - Phillip A Gribble
- Department of Rehabilitation Sciences, University of Kentucky, Lexington
| | - Brian G Pietrosimone
- Department of Exercise and Sport Science, University of North Carolina at Chapel Hill. Dr McLeod is now with the Department of Health and Human Performance, College of Charleston, SC
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24
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Masugi Y, Kitamura T, Kamibayashi K, Ogawa T, Ogata T, Kawashima N, Nakazawa K. Velocity-dependent suppression of the soleus H-reflex during robot-assisted passive stepping. Neurosci Lett 2015; 584:337-41. [PMID: 25449873 DOI: 10.1016/j.neulet.2014.10.044] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2014] [Revised: 09/17/2014] [Accepted: 10/26/2014] [Indexed: 11/22/2022]
Abstract
The amplitude of the Hoffmann (H)-reflex in the soleus (Sol) muscle is known to be suppressed during passive stepping compared with during passive standing. The reduction of the H-reflex is not due to load-related afferent inputs, but rather to movement-related afferent inputs from the lower limbs. To elucidate the underlying neural mechanisms of this inhibition, we investigated the effects of the stepping velocity on the Sol H-reflex during robot-assisted passive stepping in 11 healthy subjects. The Sol H-reflexes were recorded during passive standing and stepping at five stepping velocities (stride frequencies: 14, 21, 28, 35, and 42 min(-1)) in the air. The Sol H-reflexes were significantly inhibited during passive stepping as compared with during passive standing, and reduced in size as the stepping velocity increased. These results indicate that the extent of H-reflex suppression increases with increasing movement-related afferent inputs from the lower limbs during passive stepping. The velocity dependence suggests that the Ia afferent inputs from lower-limb muscles around the hip and knee joints are most probably related to this inhibition.
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25
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Laine CM, Yavuz ŞU, Farina D. Task-related changes in sensorimotor integration influence the common synaptic input to motor neurones. Acta Physiol (Oxf) 2014; 211:229-39. [PMID: 24620727 DOI: 10.1111/apha.12255] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Revised: 11/14/2013] [Accepted: 02/02/2014] [Indexed: 01/05/2023]
Abstract
AIM The purpose of this investigation was to understand how visual information, when used to guide muscle activity, influences the frequency content of the neural drive to muscles and the gain of afferent feedback. METHODS Subjects maintained static, isometric contractions of the tibialis anterior muscle by matching a visual display of their ankle dorsiflexion force to a target set at 10% of their maximum voluntary contraction level. Two visual feedback conditions were studied. The first was a high-sensitivity feedback, in which small changes in force were of large on-screen visual magnitude. The second was a low-sensitivity feedback, in which the on-screen scaling of feedback was reduced by a factor of 10, making small force fluctuations difficult to perceive. Force tremor and Hoffmann reflex (H-reflex) amplitudes were compared between the two conditions, as well as coherence among single motor unit spike trains derived from high-density EMG recordings. RESULTS The high-sensitivity feedback condition was associated with lower error, larger force tremor (4-12 Hz) and larger H-reflex amplitudes relative to the low-sensitivity feedback condition. In addition, the use of high-sensitivity feedback was associated with lower 1-5 Hz coherence among pairs of motor units, but larger coherence at high frequencies (6-12, approx. 20, >30 Hz). CONCLUSION Alteration of visual feedback influences nearly the entire frequency spectrum of common input to motor neurones, as well the gain of afferent feedback. We speculate that task-related modulation of afferent feedback could be the origin of many of the observed changes in the neural drive to muscles.
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Affiliation(s)
- C. M. Laine
- Department of Neurorehabilitation Engineering; Bernstein Focus Neurotechnology (BFNT) Göttingen; Bernstein Centre for Computational Neuroscience (BCCN); University Medical Center Göttingen; Georg-August University; Göttingen Germany
| | - Ş. U. Yavuz
- Department of Neurorehabilitation Engineering; Bernstein Focus Neurotechnology (BFNT) Göttingen; Bernstein Centre for Computational Neuroscience (BCCN); University Medical Center Göttingen; Georg-August University; Göttingen Germany
- Department of Orthobionics; Georg-August University; Göttingen Germany
| | - D. Farina
- Department of Neurorehabilitation Engineering; Bernstein Focus Neurotechnology (BFNT) Göttingen; Bernstein Centre for Computational Neuroscience (BCCN); University Medical Center Göttingen; Georg-August University; Göttingen Germany
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26
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Horslen BC, Murnaghan CD, Inglis JT, Chua R, Carpenter MG. Effects of postural threat on spinal stretch reflexes: evidence for increased muscle spindle sensitivity? J Neurophysiol 2013; 110:899-906. [PMID: 23719208 DOI: 10.1152/jn.00065.2013] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Standing balance is often threatened in everyday life. These threats typically involve scenarios in which either the likelihood or the consequence of falling is higher than normal. When cats are placed in these scenarios they respond by increasing the sensitivity of muscle spindles imbedded in the leg muscles, presumably to increase balance-relevant afferent information available to the nervous system. At present, it is unknown whether humans also respond to such postural threats by altering muscle spindle sensitivity. Here we present two studies that probed the effects of postural threat on spinal stretch reflexes. In study 1 we manipulated the threat associated with an increased consequence of a fall by having subjects stand at the edge of an elevated surface (3.2 m). In study 2 we manipulated the threat by increasing the likelihood of a fall by occasionally tilting the support surface on which subjects stood. In both scenarios we used Hoffmann (H) and tendon stretch (T) reflexes to probe the spinal stretch reflex circuit of the soleus muscle. We observed increased T-reflex amplitudes and unchanged H-reflex amplitudes in both threat scenarios. These results suggest that the synaptic state of the spinal stretch reflex is unaffected by postural threat and that therefore the muscle spindles activated in the T-reflexes must be more sensitive in the threatening conditions. We propose that this increase in sensitivity may function to satisfy the conflicting needs to restrict movement with threat, while maintaining a certain amount of sensory information related to postural control.
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Affiliation(s)
- Brian C Horslen
- School of Kinesiology, The University of British Columbia, Vancouver, British Columbia, Canada
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Hoffman M, Harter RA, Hayes BT, Wojtys EM, Murtaugh P. The interrelationships among sex hormone concentrations, motoneuron excitability, and anterior tibial displacement in women and men. J Athl Train 2008; 43:364-72. [PMID: 18668169 DOI: 10.4085/1062-6050-43.4.364] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
CONTEXT Sex hormone fluctuations have been implicated as a contributing factor to the high rates of noncontact injury to the anterior cruciate ligament in females. OBJECTIVE To determine the strength of the relationships among variables of sex hormone concentrations, motoneuron excitability, and anterior tibial displacement (ATD) in women and men and to determine if these relationships differ between the sexes. DESIGN Cohort study. SETTING Sports medicine laboratory. PATIENTS OR OTHER PARTICIPANTS Twenty-eight regularly menstruating women (age = 22.4 +/- 3.4 years) and 15 men (age = 22.3 +/- 3.7 years) participated in the study. INTERVENTION(S) Fluctuations in sex hormones were determined for the participants. Female participants were tested every other day of their menstrual cycles, whereas male participants were tested every fourth day during the 28-day period. MAIN OUTCOME MEASURE(S) We measured Hoffmann reflexes (maximum Hoffmann reflex [H(max)] to maximum M-wave [M(max)] ratio in the soleus), ATD under a 134-N load, and saliva concentrations of estrogen and progesterone. The independent variable was sex. Pearson product moment correlation coefficients were calculated for each participant by pairing measurements made on the same day. Two-tailed independent-samples t tests were used to determine the difference between the male and female correlations for each variable. RESULTS Over the course of the study, the relationships between H(max)ratioM(max) and estrogen, H(max)ratioM(max) and progesterone, ATD and estrogen, and ATD and progesterone were not different between the sexes. However, the relationship between ATD and progesterone was different between the sexes (P = .036). CONCLUSIONS The observed correlations did not support our hypothesis that the relationships between sex hormone levels and reflex activity or between sex hormone levels and ATD would be different for women compared with men. If sex hormone concentrations significantly contribute to anterior cruciate ligament ruptures because of changes in laxity or in motoneuron excitability, their mechanism of action is likely multifactorial and complex.
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Affiliation(s)
- Mark Hoffman
- Sports Medicine Laboratory, Oregon State University, Corvallis, OR 97331-3303, USA.
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