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Chen Y, Hu CL, Hong CK, Hsu KL, Kuan FC, Chen WL, Su WR, Chen YC, Hwang IS. Deficits in neuromuscular control of increasing force in patients with chronic lateral epicondylitis. Front Physiol 2023; 14:1178557. [PMID: 37637142 PMCID: PMC10450945 DOI: 10.3389/fphys.2023.1178557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 08/02/2023] [Indexed: 08/29/2023] Open
Abstract
Objective: This study investigated the neuromuscular control of increasing and releasing force in patients with chronic lateral epicondylitis (CLE). Methods: Fifteen patients with CLE (10 males, 5 females, 46.5 ± 6.3 years) and fifteen healthy participants (9 males, 6 females, 45.3 ± 2.5 years) participated in this study. In addition to power grip and maximal voluntary contraction (MVC) of wrist extension, force fluctuation dynamics and characteristics of inter-spike intervals (ISI) of motor units (MUs) with various recruitment thresholds in the extensor carpi radialis brevis (ECRB) and extensor carpi radialis longus (ECRL) during a designated force-tracking task with a trapezoidal target (0%-75%-0% MVC) were assessed. Results: Besides a smaller MVC of wrist extension, the patients exhibited significantly greater task errors (p = 0.007) and force fluctuations (p = 0.001) during force increment than the healthy counterparts. Nevertheless, no force variables significantly differed between groups during force release (p > 0.05). During force increment, the amplitudes of the motor unit action potential of the ECRB and ECRL muscles of the patients were smaller than those of the heathy counterparts (p < 0.001). The patient group also exhibited a higher percentage of motor units (MU) with lower recruitment threshold (<5% MVC) in the ECRL/ECRB muscles and a lower percentage of MU with higher recruitment threshold (>40% MVC) in the ECRB muscle, compared to the healthy group. During force increment, the patient group exhibited a higher rate of decrease in inter-spike intervals (ISIs) of motor units with lower recruitment thresholds (<10% MVC) in the ECRB and ECRL muscles, compared to the control group (p < 0.005). Conclusion: The patients with CLE exhibited more pronounced impairment in increasing force than in releasing force. This impairment in increasing force is attributed to deficits in tendon structure and degenerative changes in the larger motor units of the wrist extensors. To compensate for the neuromuscular deficits, the rate of progressive increase in discharge rate of the remaining smaller motor units (MUs) is enhanced to generate force. Significance: The deficits in neuromuscular control observed in CLE with degenerative changes cannot be fully explained by the experimental pain model, which predicts pain-related inhibition on low-threshold motor units.
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Affiliation(s)
- Yueh Chen
- Institute of Allied Health Sciences, College of Medicine, National Cheng-Kung University, Tainan, Taiwan
- Department of Orthopedics, Madou Sin-Lâu Hospital, Tainan, Taiwan
| | - Chia-Ling Hu
- Institute of Allied Health Sciences, College of Medicine, National Cheng-Kung University, Tainan, Taiwan
| | - Chih-Kai Hong
- Department of Orthopaedic Surgery, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Kai-Lan Hsu
- Department of Orthopaedic Surgery, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Fa-Chuan Kuan
- Department of Orthopaedic Surgery, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Wei-Li Chen
- Department of Orthopedics, Madou Sin-Lâu Hospital, Tainan, Taiwan
| | - Wei-Ren Su
- Department of Orthopaedic Surgery, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Musculoskeletal Research Center, Innovation Headquarter, National Cheng Kung University, Tainan, Taiwan
| | - Yi-Ching Chen
- Department of Physical Therapy, College of Medical Science and Technology, Chung Shan Medical University, Taichung, Taiwan
| | - Ing-Shiou Hwang
- 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
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Hill CE, Heales LJ, Stanton R, Holmes MWR, Kean CO. Effects of multidirectional elastic tape on forearm muscle activity and wrist extension during submaximal gripping in individuals with lateral elbow tendinopathy: A randomised crossover trial. Clin Biomech (Bristol, Avon) 2022; 100:105810. [PMID: 36327545 DOI: 10.1016/j.clinbiomech.2022.105810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 10/11/2022] [Accepted: 10/21/2022] [Indexed: 02/07/2023]
Abstract
BACKGROUND Lateral elbow tendinopathy is associated with changes to forearm muscle activity and wrist posture during gripping. Multidirectional elastic tape is thought to exert a deloading effect on underlying musculotendinous structures, which could potentially alter muscle activity or wrist posture. METHODS This single-blinded randomised crossover trial compared the immediate effects of tensioned multidirectional elastic tape, untensioned control tape, and no tape, in individuals with lateral elbow tendinopathy. Muscle activity of extensor carpi radialis longus and brevis, extensor carpi ulnaris, and extensor digitorum and wrist extension angle were recorded during a submaximal gripping task. Muscle activity was normalised to the maximum amplitude recorded during maximal grip. Change scores were calculated (post-condition minus baseline). Repeated-measure analyses of variance were used to examine between-condition differences. FINDINGS 27 participants (16 males, mean age (SD): 48.6 (11.9) years) underwent all conditions. Extensor digitorum muscle activity was reduced during the multidirectional elastic tape, compared to control tape and no tape (MD -5.6% [95%CI: -9.9 to -1.3], MD -5.8% [95%CI: -10.2 to -1.4], respectively). Extensor carpi ulnaris muscle activity was reduced during the multidirectional elastic tape, compared to the control tape (mean difference [MD] -3.2% [95%CI: -5.3 to -1.1]), but increased during the control tape, compared to the no tape (MD 2.9% [95%CI: 0.8 to 5.0]). No differences were observed in extensor carpi radialis brevis or longus muscle activity, or extension wrist angle between conditions. INTERPRETATION A decreased in extensor carpi ulnaris and extensor digitorum muscle activity during multidirectional elastic tape may be evidence of a deloading effect during submaximal gripping.
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Affiliation(s)
- Caitlin E Hill
- School of Health, Medical and Applied Sciences, Central Queensland University, Norman Gardens, QLD, Australia
| | - Luke J Heales
- School of Health, Medical and Applied Sciences, Central Queensland University, Norman Gardens, QLD, Australia
| | - Robert Stanton
- School of Health, Medical and Applied Sciences, Central Queensland University, Norman Gardens, QLD, Australia; Appleton Institute, Central Queensland University, Adelaide, SA, Australia
| | - Michael W R Holmes
- Faculty of Applied Health Sciences, Brock University, St. Catharines, ON, Canada
| | - Crystal O Kean
- School of Health, Medical and Applied Sciences, Central Queensland University, Norman Gardens, QLD, Australia.
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Cooke N, Obst S, Vicenzino B, Hodges PW, Heales LJ. Upper limb position affects pain-free grip strength in individuals with lateral elbow tendinopathy. PHYSIOTHERAPY RESEARCH INTERNATIONAL 2021; 26:e1906. [PMID: 33772973 DOI: 10.1002/pri.1906] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 02/07/2021] [Accepted: 03/09/2021] [Indexed: 11/06/2022]
Abstract
BACKGROUND AND PURPOSE Pain-free grip (PFG) force is commonly used to monitor treatment outcomes in lateral elbow tendinopathy (LET); however, it is unclear whether changes in forearm and elbow position affect PFG force values. This study aims to examine the effect of elbow/shoulder and forearm position on non-normalised and normalised PFG force in individuals with unilateral LET. METHODS A cohort study including 21 subjects with clinically diagnosed unilateral LET (13 females, mean [SD] age 50 [8] years) performed PFG force (symptomatic arm) and maximal grip (asymptomatic arm) tasks using four upper limb positions: (1) shoulder neutral, elbow flexed (90°), forearm pronated; (2) shoulder neutral, elbow flexed (90°), forearm neutral; (3) shoulder flexed (90°), elbow extended, forearm pronated; and (4) shoulder flexed (90°), elbow extended, forearm neutral. PFG force was normalised to the maximal grip of the asymptomatic side. Repeated-measures analyses of variance were used to compare non-normalised and PFG force normalised to maximal grip between positions. RESULTS Both non-normalised and normalised PFG forces were greater in position 2 than position 1, position 3 and position 4 (elbow-by-forearm interaction non-normalised p = 0.002, normalised p = 0.004). There were no differences between positions 1, 3 and 4 for either non-normalised or normalised PFG strength. DISCUSSION This study shows that PFG force was higher when performed with forearm neutral supination/pronation, elbow flexion and shoulder neutral than other tested positions, and irrespective of whether PFG force was normalised to the maximal grip force of the contralateral limb. This indicates that arm position should be standardised for comparison.
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Affiliation(s)
- Nikki Cooke
- College of Health Sciences, School of Health, Medical and Applied Sciences, Central Queensland University, Rockhampton, Australia
| | - Steven Obst
- College of Health Sciences, School of Health, Medical and Applied Sciences, Central Queensland University, Bundaberg, Australia
| | - Bill Vicenzino
- NHMRC Centre of Clinical Research Excellence in Spinal Pain, Injury and Health, School of Health and Rehabilitation Science, The University of Queensland, Brisbane, Australia
| | - Paul W Hodges
- NHMRC Centre of Clinical Research Excellence in Spinal Pain, Injury and Health, School of Health and Rehabilitation Science, The University of Queensland, Brisbane, Australia
| | - Luke J Heales
- College of Health Sciences, School of Health, Medical and Applied Sciences, Central Queensland University, Rockhampton, Australia
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Heales LJ, McClintock SR, Maynard S, Lems CJ, Rose JA, Hill C, Kean CO, Obst S. Evaluating the immediate effect of forearm and wrist orthoses on pain and function in individuals with lateral elbow tendinopathy: A systematic review. Musculoskelet Sci Pract 2020; 47:102147. [PMID: 32452393 DOI: 10.1016/j.msksp.2020.102147] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 02/18/2020] [Accepted: 03/02/2020] [Indexed: 11/16/2022]
Abstract
BACKGROUND Lateral elbow tendinopathy is associated with pain during gripping, with forearm/wrist orthoses prescribed for treatment. OBJECTIVES To investigate the immediate effects of forearm and/or wrist orthoses on outcome measures of pain and function in individuals with lateral elbow tendinopathy. DESIGN Systematic review METHODS: Four electronic databases were searched to identify randomised controlled trials reporting the immediate effects of forearm and/or wrist orthoses on pain and function in individuals with lateral elbow tendinopathy. The quality of evidence was rated from high to very low, using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) for the primary outcomes. Where possible, standardised mean difference (SMD) and 95% confidence intervals were calculated to compare post measures between forearm and/or wrist orthoses and control/placebo conditions. RESULTS The search revealed 1965 studies, of which, seven randomised crossover trials were included. Using the GRADE approach there was low quality evidence revealing a significant decrease in pain during contraction (SMD range -0.65 to -0.83) with forearm orthoses compared to a control/placebo condition. Low quality evidence revealed improvements in pain-free grip strength with the use of a forearm orthosis (SMD range 0.24-0.38), but not maximal grip strength (SMD range 0.14-0.15). Low quality evidence revealed a static wrist orthosis did not improve pain-free grip strength (SMD -0.08) or maximal grip strength (SMD -0.22). CONCLUSION There is low quality evidence that forearm orthoses can immediately reduce pain during contraction and improve pain-free grip strength but not maximal grip strength in individuals with lateral elbow tendinopathy.
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Affiliation(s)
- Luke J Heales
- Central Queensland University, School of Health, Medical and Applied Sciences, Department of Health and Exercise Science, Rockhampton, 4701, Queensland, Australia.
| | - Stacy R McClintock
- Central Queensland University, School of Health, Medical and Applied Sciences, Department of Health and Exercise Science, Rockhampton, 4701, Queensland, Australia.
| | - Sabrina Maynard
- Central Queensland University, School of Health, Medical and Applied Sciences, Department of Health and Exercise Science, Rockhampton, 4701, Queensland, Australia.
| | - Cooper J Lems
- Central Queensland University, School of Health, Medical and Applied Sciences, Department of Health and Exercise Science, Rockhampton, 4701, Queensland, Australia.
| | - Jordan A Rose
- Central Queensland University, School of Health, Medical and Applied Sciences, Department of Health and Exercise Science, Rockhampton, 4701, Queensland, Australia.
| | - Caitlin Hill
- Central Queensland University, School of Health, Medical and Applied Sciences, Department of Health and Exercise Science, Rockhampton, 4701, Queensland, Australia.
| | - Crystal O Kean
- Central Queensland University, School of Health, Medical and Applied Sciences, Department of Health and Exercise Science, Rockhampton, 4701, Queensland, Australia.
| | - Steven Obst
- Central Queensland University, School of Health, Medical and Applied Sciences, Department of Health and Exercise Science, Bundaberg, 4670, Queensland, Australia.
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Rojas-Martínez M, Alonso JF, Jordanić M, Mañanas MÁ, Chaler J. Analysis of Muscle Load-Sharing in Patients With Lateral Epicondylitis During Endurance Isokinetic Contractions Using Non-linear Prediction. Front Physiol 2019; 10:1185. [PMID: 31632282 PMCID: PMC6779029 DOI: 10.3389/fphys.2019.01185] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 09/02/2019] [Indexed: 11/24/2022] Open
Abstract
The aim of this paper is to analyze muscle load-sharing in patients with Lateral Epicondylitis during dynamic endurance contractions by means of non-linear prediction of surface EMG signals. The proposed non-linear cross-prediction scheme was used to predict the envelope of an EMG signal and is based on locally linear models built in a lag-embedded Euclidean space. The results were compared with a co-activation index, a common measure based on the activation of a muscle pair. Non-linear prediction revealed changes in muscle coupling, that is load-sharing, over time both in a control group and Lateral Epicondylitis (p < 0.05), even when subjects did not report pain at the end of the exercise. These changes were more pronounced in patients, especially in the first part of the exercise and up to 50% of the total endurance time (p < 0.05). By contrast, the co-activation index showed no differences between groups. Results reflect the changing nature of muscular activation strategy, presumably because of the mechanisms triggered by fatigue. Strategies differ between controls and patients, pointing to an altered coordination in Lateral Epicondylitis.
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Affiliation(s)
- Mónica Rojas-Martínez
- Department of Bioengineering, Faculty of Engineering, Universidad El Bosque, Bogotá, Colombia
| | - Joan Francesc Alonso
- Biomedical Research Networking Centre in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Biomedical Engineering Research Centre (CREB), Department of Automatic Control (ESAII), Universitat Politècnica de Catalunya (UPC), Barcelona, Spain
| | - Mislav Jordanić
- Biomedical Research Networking Centre in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Biomedical Engineering Research Centre (CREB), Department of Automatic Control (ESAII), Universitat Politècnica de Catalunya (UPC), Barcelona, Spain
| | - Miguel Ángel Mañanas
- Biomedical Research Networking Centre in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Biomedical Engineering Research Centre (CREB), Department of Automatic Control (ESAII), Universitat Politècnica de Catalunya (UPC), Barcelona, Spain
| | - Joaquim Chaler
- PM&R Department, Egarsat, Terrassa, Spain.,EUSES-Bellvitge, Universitat de Girona, Universitat de Barcelona, ENTI, Barcelona, Spain
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George CE, Heales LJ, Stanton R, Wintour SA, Kean CO. Sticking to the facts: A systematic review of the effects of therapeutic tape in lateral epicondylalgia. Phys Ther Sport 2019; 40:117-127. [PMID: 31518778 DOI: 10.1016/j.ptsp.2019.08.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2019] [Revised: 05/17/2019] [Accepted: 08/26/2019] [Indexed: 12/31/2022]
Abstract
OBJECTIVE To systematically identify, appraise, and examine evidence regarding the effects of therapeutic tape on pain and function in individuals with lateral epicondylalgia (LE). METHODS Five electronic databases were systematically searched up to March 2018. Full-text, peer-reviewed, English-language studies were included if they had an LE population, a standalone tape condition, and an outcome related to pain or function. RESULTS Eight out of 2022 screened studies were included. Three studies demonstrated immediate (i.e. within 1 h) improvements in pain and pain-free grip strength following diamond deloading rigid tape. One study reported immediate improvements in proprioception following transverse rigid tape. The immediate effects of longitudinal kinesiotape were inconsistent. One study reported improvements in pain and pain-free grip strength, while another study reported no effect on pain, strength, or muscle activity. Two studies examined short-term (i.e. within six weeks) kinesiotape application. One study reported two weeks of longitudinal kinesiotape improved pain and maximum grip strength. The other study reported one week of diamond kinesiotape improved patient-reported pain and function, but not maximum grip strength. CONCLUSIONS In individuals with LE, diamond deloading rigid tape may immediately improve pain and strength. There is conflicting evidence regarding kinesiotape effects in both immediate and short-term timeframes.
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Affiliation(s)
- Caitlin E George
- School of Health, Medical and Applied Sciences, Central Queensland University, Rockhampton, Australia
| | - Luke J Heales
- School of Health, Medical and Applied Sciences, Central Queensland University, Rockhampton, Australia; School of Biomedical Sciences, University of Queensland, Brisbane, Australia
| | - Robert Stanton
- School of Health, Medical and Applied Sciences, Central Queensland University, Rockhampton, Australia; Appleton Institute, Central Queensland University, Adelaide, Australia
| | - Sally-Anne Wintour
- School of Health, Medical and Applied Sciences, Central Queensland University, Rockhampton, Australia
| | - Crystal O Kean
- School of Health, Medical and Applied Sciences, Central Queensland University, Rockhampton, Australia.
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Bordachar D. Lateral epicondylalgia: A primary nervous system disorder. Med Hypotheses 2019; 123:101-109. [PMID: 30696578 DOI: 10.1016/j.mehy.2019.01.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 12/28/2018] [Accepted: 01/10/2019] [Indexed: 01/05/2023]
Abstract
Lateral epicondylalgia (LE) is the most common chronic painful condition affecting the elbow in the general population. Although major advances have been accomplished in recent years in the understanding of LE, the underlying physiopathology is still a reason for debate. Differences in clinical presentation and evolution of the symptoms among patients, suggest the need for revisiting the current knowledge about subjacent mechanisms that attempt to explain pain and functional loss. Previous models have suggested that the condition is mainly a degenerative tendinopathy, associated with changes in pain pathways and the motor system. The hypothesis of this work is that LE is the clinical manifestation of a primary nervous system disorder, characterized by an abnormal increase in neuronal activity and a subsequent loss of homeostasis, which secondarily affects the musculoskeletal tissues of the elbow-forearm-hand complex. A new model for LE is presented, supported by an in-deep analysis of basic sciences, epidemiological and clinical studies.
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Affiliation(s)
- Diego Bordachar
- Instituto Universitario del Gran Rosario (IUGR), Centro Universitario de Asistencia, Docencia e Investigación (CUADI), Unidad de Investigación Musculoesquelética (UIM), Argentina.
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Sethi K, Noohu MM. Scapular muscles strengthening on pain, functional outcome and muscle activity in chronic lateral epicondylalgia. J Orthop Sci 2018; 23:777-782. [PMID: 29958726 DOI: 10.1016/j.jos.2018.05.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 05/03/2018] [Accepted: 05/12/2018] [Indexed: 02/09/2023]
Abstract
AIM The aim of the study was to investigate the effect of lower trapezius (LT), middle trapezius (MT) and serratus anterior (SA) strengthening on pain, pain free grip strength, functional outcome, scapular muscles strength, scapular position and electromyographic (EMG) activity of lower trapezius, serratus anterior, extensor carpi radialis brevis (ECRB) and extensor digitorum communis (EDC) in individuals with chronic lateral epicondylalgia (LE). METHODS Twenty six patients with chronic lateral epicondylalgia were recruited. Subjects were divided into two groups. Group 1 received scapular muscles strengthening along with conventional physiotherapy and Group 2 received only conventional physiotherapy for 6 weeks. Subjects were measured for pain (VAS), pain free grip strength, functional outcome (PRTEE), scapular muscle strength, scapular positioning (LSST) and EMG activity before and after the intervention.2 × 2 mixed ANOVA was used to investigate for main effect of time and group and interaction effect (time × group). RESULTS The results revealed that there was statistically significant difference for time effect for all the outcome measures. In time × group interaction there was significant difference for all the outcome measures except scapular position (LSST3). Significant difference for group effect was observed in EMG activity of LT and ECRB. CONCLUSION The scapular muscle strengthening should be used along with the conventional physiotherapy in individuals with chronic LE to improve pain, pain free grip strength, functional outcome, muscle strength, scapular position and muscle activity.
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Affiliation(s)
- Kritika Sethi
- Centre for Physiotherapy and Rehabilitation Sciences, Jamia Milllia Islamia, New Delhi, 110025 India
| | - Majumi M Noohu
- Centre for Physiotherapy and Rehabilitation Sciences, Jamia Milllia Islamia, New Delhi, 110025 India.
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Manickaraj N, Bisset LM, Devanaboyina VSPT, Kavanagh JJ. Chronic pain alters spatiotemporal activation patterns of forearm muscle synergies during the development of grip force. J Neurophysiol 2017; 118:2132-2141. [PMID: 28724779 DOI: 10.1152/jn.00210.2017] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 07/18/2017] [Accepted: 07/18/2017] [Indexed: 02/04/2023] Open
Abstract
It is largely unknown how the CNS regulates multiple muscle systems in the presence of pain. This study used muscle synergy analysis to investigate multiple forearm muscles in individuals with chronic elbow pain during the development of grip force. Eleven individuals with chronic elbow pain and 11 healthy age-matched control subjects developed grip force to 15% and 30% of maximum voluntary contraction (MVC). Surface electromyography was obtained from six forearm muscles during force development before nonnegative matrix factorization was performed. The relationship between muscle synergies and standard clinical tests of elbow pain were examined by linear regression. During grip force development to 15% MVC the pain group had a lower number of forearm muscle synergies, increased similarity in spatial activation patterns, increased cocontraction of forearm flexors, and a greater magnitude of muscle weightings across the forearm when performing the task. During the 30% MVC grip the numbers of muscle synergies were the same for both groups; however, the pain group had lower activation and reduced variability in the timing of peak activation. The timing of peak activation was delayed in the pain group regardless of the task, and performing the grip in different wrist postures did not affect muscle synergy characteristics in either group. Although localized pain causes direct dysfunction of an affected muscle, this study provides evidence that the timing and amplitude of agonist and antagonist muscle activity are also affected with chronic pain.NEW & NOTEWORTHY Muscle activation patterns of individuals with chronic elbow pain are simplified compared with healthy individuals. This is apparent as individuals with pain exhibit fewer forearm muscle synergies, and increased similarity of activation patterns between forearm muscles, when performing pain-free isometric gripping. As such, even during pain-free tasks it is possible to observe changes in motor control in people with chronic pain.
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Affiliation(s)
- Nagarajan Manickaraj
- Menzies Health Institute Queensland, Griffith University, Southport, Queensland, Australia
| | - Leanne M Bisset
- Menzies Health Institute Queensland, Griffith University, Southport, Queensland, Australia
| | | | - Justin J Kavanagh
- Menzies Health Institute Queensland, Griffith University, Southport, Queensland, Australia
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Heales LJ, Hug F, MacDonald DA, Vicenzino B, Hodges PW. Is synergistic organisation of muscle coordination altered in people with lateral epicondylalgia? A case-control study. Clin Biomech (Bristol, Avon) 2016; 35:124-31. [PMID: 27179317 DOI: 10.1016/j.clinbiomech.2016.04.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Revised: 04/26/2016] [Accepted: 04/29/2016] [Indexed: 02/07/2023]
Abstract
BACKGROUND Lateral epicondylalgia is a common musculoskeletal disorder and is associated with deficits in the motor system including painful grip. This study compared coordination of forearm muscles (muscle synergies) during repeated gripping between individuals with and without lateral epicondylalgia. METHODS Twelve participants with lateral epicondylalgia and 14 controls performed 15 cyclical repetitions of sub-maximal (20% maximum grip force of asymptomatic arm), pain free dynamic gripping in four arm positions: shoulder neutral with elbow flexed to 90° and shoulder flexed to 90° with elbow extended both with forearm pronated and neutral. Muscle activity was recorded from extensor carpi radialis brevis/longus, extensor digitorum, flexor digitorum superficialis/profundus, and flexor carpi radialis, with intramuscular electrodes. Muscle synergies were extracted using non-negative matrix factorisation. FINDINGS Analysis of each position and participant, demonstrated that two muscle synergies accounted for >97% of the variance for both groups. Between-group differences were identified after electromyography patterns of the control group were used to reconstruct the patterns of the lateral epicondylalgia group. A greater variance accounted for was identified for the controls than lateral epicondylalgia (p=0.009). This difference might be explained by an additional burst of flexor digitorum superficialis electromyography during grip release in many lateral epicondylalgia participants. INTERPRETATION These data provide evidence of some differences in synergistic organisation of activation of forearm muscles between individuals with and without lateral epicondylalgia. Due to study design it is not possible to elucidate whether changes in the coordination of muscle activity during gripping are associated with the cause or effect of lateral epicondylalgia.
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Affiliation(s)
- Luke James Heales
- University of Queensland, NHMRC Centre of Clinical Research Excellence in Spinal Pain, Injury and Health, School of Health and Rehabilitation Science, Brisbane, Australia; Central Queensland University, School of Human, Health and Social Sciences, Division of Physiotherapy, Rockhampton, Australia.
| | - François Hug
- University of Queensland, NHMRC Centre of Clinical Research Excellence in Spinal Pain, Injury and Health, School of Health and Rehabilitation Science, Brisbane, Australia; University of Nantes, Laboratory EA, 4334, Nantes, France.
| | - David Alan MacDonald
- University of Queensland, NHMRC Centre of Clinical Research Excellence in Spinal Pain, Injury and Health, School of Health and Rehabilitation Science, Brisbane, Australia.
| | - Bill Vicenzino
- University of Queensland, NHMRC Centre of Clinical Research Excellence in Spinal Pain, Injury and Health, School of Health and Rehabilitation Science, Brisbane, Australia.
| | - Paul William Hodges
- University of Queensland, NHMRC Centre of Clinical Research Excellence in Spinal Pain, Injury and Health, School of Health and Rehabilitation Science, Brisbane, Australia.
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