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Debenham MIB, Bruce CB, McNeil CJ, Dalton BH. Four hours of normobaric hypoxia reduces Achilles tendon reflex inhibition. J Appl Physiol (1985) 2024; 136:1468-1477. [PMID: 38601996 DOI: 10.1152/japplphysiol.00592.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 03/18/2024] [Accepted: 04/02/2024] [Indexed: 04/12/2024] Open
Abstract
Acute exposure to hypoxia increases postural sway, but the underlying neurophysiological factors are unclear. Golgi tendon organs (GTOs), located within the musculotendinous junction (MTJ), provide inhibitory signals to plantar flexor muscles that are important for balance control; however, it is uncertain if GTO function is influenced by hypoxia. The aim of this study was to determine how normobaric hypoxia influences lower limb tendon-evoked inhibitory reflexes during upright stance. We hypothesized that tendon-evoked reflex area and duration would decrease during hypoxia, indicating less inhibition of postural muscles compared with normoxia. At baseline (BL; 0.21 fraction of inspired oxygen, FIO2) and at ∼2 (H2) and 4 (H4) h of normobaric hypoxia (0.11 FIO2) in a normobaric hypoxic chamber, 16 healthy participants received electrical musculotendinous stimulation (MTstim) to the MTJ of the left Achilles tendon. The MTstim was delivered as two sets of 50 stimuli while the participant stood on a force plate with their feet together. Tendon-evoked inhibitory reflexes were recorded from the surface electromyogram of the ipsilateral medial gastrocnemius, and center of pressure (CoP) variables were recorded from the force plate. Normobaric hypoxia increased CoP velocity (P ≤ 0.002) but not CoP standard deviation (P ≥ 0.12). Compared with BL, normobaric hypoxia reduced tendon-evoked inhibitory reflex area by 45% at H2 and 53% at H4 (P ≤ 0.002). In contrast, reflex duration was unchanged during hypoxia. The reduced inhibitory feedback from the GTO pathway could likely play a role in the increased postural sway observed during acute exposure to hypoxia.NEW & NOTEWORTHY The Ib pathway arising from the Golgi tendon organ provides inhibitory signals onto motor neuron pools that modifies force and, hence, postural control. Although hypoxia influences standing balance (increases sway), the underlying mechanisms have yet to be unraveled. Our study identified that tendon-evoked inhibition onto a plantar flexor motoneuron pool is reduced by acute exposure to normobaric hypoxia. This reduction of inhibition may contribute to the hypoxia-related increase in postural sway.
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Affiliation(s)
- Mathew I B Debenham
- Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Sciences, The University of British Columbia, Kelowna, British Columbia, Canada
| | - Christina B Bruce
- Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Sciences, The University of British Columbia, Kelowna, British Columbia, Canada
| | - Chris J McNeil
- Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Sciences, The University of British Columbia, Kelowna, British Columbia, Canada
| | - Brian H Dalton
- Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Sciences, The University of British Columbia, Kelowna, British Columbia, Canada
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Barjandi G, Svedenlöf J, Jasim H, Collin M, Hedenberg-Magnusson B, Christidis N, Ernberg M. Clinical aspects of mastication myalgia-an overview. FRONTIERS IN PAIN RESEARCH 2024; 4:1306475. [PMID: 38264542 PMCID: PMC10803665 DOI: 10.3389/fpain.2023.1306475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Accepted: 12/26/2023] [Indexed: 01/25/2024] Open
Abstract
Mastication myalgia is the most common cause of non-odontogenic pain in the orofacial region and is often associated with a reduced quality of life. The purpose of this review is to provide an overview of the clinical aspects of myalgia based on available research. The review includes epidemiological, diagnostic, and etiological aspects. In addition, the potential risk factors related to the transition from acute to chronic myalgia are explored and treatment strategies are presented for its management. As a result, this review may increase clinical knowledge about mastication myalgia and clarify strategies regarding prevention, diagnostics, and management to improve prognosis and reduce patient suffering.
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Affiliation(s)
- Golnaz Barjandi
- Department of Dental Medicine, Karolinska Institutet, and the Scandinavian Center for Orofacial Neuroscience (SCON), Huddinge, Sweden
| | - Johanna Svedenlöf
- Department of Dental Medicine, Karolinska Institutet, and the Scandinavian Center for Orofacial Neuroscience (SCON), Huddinge, Sweden
| | - Hajer Jasim
- Department of Dental Medicine, Karolinska Institutet, and the Scandinavian Center for Orofacial Neuroscience (SCON), Huddinge, Sweden
- Department of Orofacial Pain and Jaw Function, Eastman Institute, Stockholm, Sweden
| | - Malin Collin
- Department of Dental Medicine, Karolinska Institutet, and the Scandinavian Center for Orofacial Neuroscience (SCON), Huddinge, Sweden
| | - Britt Hedenberg-Magnusson
- Department of Dental Medicine, Karolinska Institutet, and the Scandinavian Center for Orofacial Neuroscience (SCON), Huddinge, Sweden
- Department of Orofacial Pain and Jaw Function, Eastman Institute, Stockholm, Sweden
| | - Nikolaos Christidis
- Department of Dental Medicine, Karolinska Institutet, and the Scandinavian Center for Orofacial Neuroscience (SCON), Huddinge, Sweden
| | - Malin Ernberg
- Department of Dental Medicine, Karolinska Institutet, and the Scandinavian Center for Orofacial Neuroscience (SCON), Huddinge, Sweden
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Eccentric muscle contractions: from single muscle fibre to whole muscle mechanics. Pflugers Arch 2023; 475:421-435. [PMID: 36790515 PMCID: PMC10011336 DOI: 10.1007/s00424-023-02794-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 01/24/2023] [Accepted: 02/01/2023] [Indexed: 02/16/2023]
Abstract
Eccentric muscle loading encompasses several unique features compared to other types of contractions. These features include increased force, work, and performance at decreased oxygen consumption, reduced metabolic cost, improved energy efficiency, as well as decreased muscle activity. This review summarises explanatory approaches to long-standing questions in terms of muscular contraction dynamics and molecular and cellular mechanisms underlying eccentric muscle loading. Moreover, this article intends to underscore the functional link between sarcomeric components, emphasising the fundamental role of titin in skeletal muscle. The giant filament titin reveals versatile functions ranging from sarcomere organisation and maintenance, providing passive tension and elasticity, and operates as a mechanosensory and signalling platform. Structurally, titin consists of a viscoelastic spring segment that allows activation-dependent coupling to actin. This titin-actin interaction can explain linear force increases in active lengthening experiments in biological systems. A three-filament model of skeletal muscle force production (mediated by titin) is supposed to overcome significant deviations between experimental observations and predictions by the classic sliding-filament and cross-bridge theories. Taken together, this review intends to contribute to a more detailed understanding of overall muscle behaviour and force generation-from a microscopic sarcomere level to a macroscopic multi-joint muscle level-impacting muscle modelling, the understanding of muscle function, and disease.
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Contento VS, Power GA. Eccentric exercise-induced muscle weakness amplifies the history dependence of force. Eur J Appl Physiol 2023; 123:749-767. [PMID: 36447012 DOI: 10.1007/s00421-022-05105-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 11/16/2022] [Indexed: 12/05/2022]
Abstract
INTRODUCTION Following active lengthening or shortening contractions, isometric steady-state torque is increased (residual force enhancement; rFE) or decreased (residual force depression; rFD), respectively, compared to fixed-end isometric contractions at the same muscle length and level of activation. Though the mechanisms underlying this history dependence of force have been investigated extensively, little is known about the influence of exercise-induced muscle weakness on rFE and rFD. PURPOSE Assess rFE and rFD in the dorsiflexors at 20%, 60%, and 100% maximal voluntary torque (MVC) and activation matching, and electrically stimulated at 20% MVC, prior to, 1 h following, and 24 h following 150 maximal eccentric dorsiflexion contractions. METHODS Twenty-six participants (13 male, 24.7 ± 2.0y; 13 female, 22.5 ± 3.6y) were seated in a dynamometer with their right hip and knee angle set to 110° and 140°, respectively, with an ankle excursion set between 0° and 40° plantar flexion (PF). MVC torque, peak twitch torque, and prolonged low frequency force depression were used to assess eccentric exercise-induced neuromuscular impairments. History-dependent contractions consisted of a 1 s isometric (40°PF or 0°PF) phase, a 1 s shortening or lengthening phase (40°/s), and an 8 s isometric (0°PF or 40°PF) phase. RESULTS Following eccentric exercise; MVC torque was decreased, prolonged low frequency force depression was present, and both rFE and rFD increased for all maximal and submaximal conditions. CONCLUSIONS The history dependence of force during voluntary torque and activation matching, and electrically stimulated contractions is amplified following eccentric exercise. It appears that a weakened neuromuscular system amplifies the magnitude of the history-dependence of force.
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Affiliation(s)
- Vincenzo S Contento
- Department of Human Health and Nutritional Sciences, College of Biological Science, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Geoffrey A Power
- Department of Human Health and Nutritional Sciences, College of Biological Science, University of Guelph, Guelph, ON, N1G 2W1, Canada.
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Pain Management and Rehabilitation for Central Sensitization in Temporomandibular Disorders: A Comprehensive Review. Int J Mol Sci 2022; 23:ijms232012164. [PMID: 36293017 PMCID: PMC9602546 DOI: 10.3390/ijms232012164] [Citation(s) in RCA: 41] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 10/07/2022] [Accepted: 10/09/2022] [Indexed: 11/24/2022] Open
Abstract
Temporomandibular disorders (TMD) are a group of musculoskeletal diseases affecting masticatory muscles and temporomandibular joints (TMJ). In this context, the chronic TMD could be considered as a condition with chronic primary orofacial pain, presenting as myofascial TMD pain or TMJ arthralgia. In this context, myogenous TMD may present overlapping features with other disorders, such as fibromyalgia and primary headaches, characterized by chronic primary pain related to dysfunction of the central nervous system (CNS), probably through the central sensitization. This phenomenon could be defined as an amplified response of the CNS to sensory stimuli and peripheral nociceptive, characterized by hyperexcitability in the dorsal horn neurons in the spinal cord, which ascend through the spinothalamic tract. The main objectives of the management of TMD patients are: decreasing pain, increasing TMJ function, and reducing the reflex masticatory muscle spasm/pain. The first-line treatments are physical therapy, pharmacological drugs, occlusal splints, laser therapy, extracorporeal shockwave therapy, transcutaneous electrical nerve stimulation, and oxygen–ozone therapy. Although all these therapeutic approaches were shown to have a positive impact on the central sensitization of TMD pain, there is still no agreement on this topic in the scientific literature. Thus, in this comprehensive review, we aimed at evaluating the evidence on pain management and rehabilitation for the central sensitization in TMD patients.
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Frischholz J, Raiteri BJ, Cresswell AG, Hahn D. Corticospinal excitability remains unchanged in the presence of residual force enhancement and does not contribute to increased torque production. PeerJ 2022; 10:e12729. [PMID: 35036100 PMCID: PMC8743010 DOI: 10.7717/peerj.12729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 12/10/2021] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Following stretch of an active muscle, muscle force is enhanced, which is known as residual force enhancement (rFE). As earlier studies found apparent corticospinal excitability modulations in the presence of rFE, this study aimed to test whether corticospinal excitability modulations contribute to rFE. METHODS Fourteen participants performed submaximal plantar flexion stretch-hold and fixed-end contractions at 30% of their maximal voluntary soleus muscle activity in a dynamometer. During the steady state of the contractions, participants either received subthreshold or suprathreshold transcranial magnetic stimulation (TMS) of their motor cortex, while triceps surae muscle responses to stimulation were obtained via electromyography (EMG), and net ankle joint torque was recorded. B-mode ultrasound imaging was used to confirm muscle fascicle stretch during stretch-hold contractions in a subset of participants. RESULTS Following stretch of the plantar flexors, an average rFE of 7% and 11% was observed for contractions with subthreshold and suprathreshold TMS, respectively. 41-46 ms following subthreshold TMS, triceps surae muscle activity was suppressed by 19-25%, but suppression was not significantly different between stretch-hold and fixed-end contractions. Similarly, the reduction in plantar flexion torque following subthreshold TMS was not significantly different between contraction conditions. Motor evoked potentials, silent periods and superimposed twitches following suprathreshold TMS were also not significantly different between contraction conditions. DISCUSSION As TMS of the motor cortex did not result in any differences between stretch-hold and fixed-end contractions, we conclude that rFE is not linked to changes in corticospinal excitability.
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Affiliation(s)
- Jasmin Frischholz
- Human Movement Science, Faculty of Sport Science, Ruhr University Bochum, Bochum, Germany
| | - Brent J. Raiteri
- Human Movement Science, Faculty of Sport Science, Ruhr University Bochum, Bochum, Germany
| | - Andrew G. Cresswell
- School of Human Movement and Nutrition Sciences, University of Queensland, Brisbane, Australia
| | - Daniel Hahn
- Human Movement Science, Faculty of Sport Science, Ruhr University Bochum, Bochum, Germany,School of Human Movement and Nutrition Sciences, University of Queensland, Brisbane, Australia
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de Campos D, Orssatto LBR, Trajano GS, Herzog W, Fontana HDB. Residual force enhancement in human skeletal muscles: A systematic review and meta-analysis. JOURNAL OF SPORT AND HEALTH SCIENCE 2022; 11:94-103. [PMID: 34062271 PMCID: PMC8847921 DOI: 10.1016/j.jshs.2021.05.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 02/21/2021] [Accepted: 03/15/2021] [Indexed: 05/05/2023]
Abstract
OBJECTIVE We reviewed and appraised the existing evidence of in vivo manifestations of residual force enhancement in human skeletal muscles and assessed, through a meta-analysis, the effect of an immediate history of eccentric contraction on the subsequent torque capacity of voluntary and electrically evoked muscle contractions. METHODS Our search was conducted from database inception to May 2020. Descriptive information was extracted from, and quality was assessed for, 45 studies. Meta-analyses and metaregressions were used to analyze residual torque enhancement and its dependence on the angular amplitude of the preceding eccentric contraction. RESULTS Procedures varied across studies with regards to muscle group tested, angular stretch amplitude, randomization of contractions, time window analyzed, and verbal command. Torque capacity in isometric (constant muscle tendon unit length and joint angle) contractions preceded by an eccentric contraction was typically greater compared to purely isometric contractions, and this effect was greater for electrically evoked muscle contractions than voluntary contractions. Residual torque enhancement differed across muscle groups for the voluntary contractions, with a significant enhancement in torque observed for the adductor pollicis, ankle dorsiflexors, ankle plantar flexors, and knee extensors, but not for the elbow and knee flexors. Meta-regressions revealed that the angular amplitude of the eccentric contraction (normalized to the respective joint's full range of motion) was not associated with the residual torque enhancement observed. CONCLUSION There is evidence of residual torque enhancement for most, but not all, muscle groups, and residual torque enhancement is greater for electrically evoked than for voluntary contractions. Contrary to our hypothesis, and contrary to generally accepted findings on isolated muscle preparations, residual torque enhancement in voluntary and electrically evoked contractions does not seem to depend on the angular amplitude of the preceding eccentric contraction.
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Affiliation(s)
- Daiani de Campos
- Biomechanics Laboratory, Federal University of Santa Catarina, Florianopolis 88040-001, Brazil
| | - Lucas B R Orssatto
- Faculty of Health, School of Exercise and Nutrition Sciences, Queensland University of Technology, Brisbane QLD 4030, Australia
| | - Gabriel S Trajano
- Faculty of Health, School of Exercise and Nutrition Sciences, Queensland University of Technology, Brisbane QLD 4030, Australia
| | - Walter Herzog
- Biomechanics Laboratory, Federal University of Santa Catarina, Florianopolis 88040-001, Brazil; Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, AB T2N 1N4, Canada
| | - Heiliane de Brito Fontana
- Biomechanics Laboratory, Federal University of Santa Catarina, Florianopolis 88040-001, Brazil; School of Biological Sciences, Federal University of Santa Catarina, Florianopolis 88040-900, Brazil.
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Maximal and submaximal isometric torque is elevated immediately following highly controlled active stretches of the hamstrings. J Electromyogr Kinesiol 2021; 56:102500. [DOI: 10.1016/j.jelekin.2020.102500] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 10/29/2020] [Accepted: 11/09/2020] [Indexed: 01/22/2023] Open
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Chapman ND, Whitting JW, Broadbent S, Crowley-McHattan ZJ, Meir R. Residual Force Enhancement Is Present in Consecutive Post-Stretch Isometric Contractions of the Hamstrings during a Training Simulation. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:1154. [PMID: 33525530 PMCID: PMC7908171 DOI: 10.3390/ijerph18031154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 01/21/2021] [Accepted: 01/25/2021] [Indexed: 11/17/2022]
Abstract
Residual force enhancement (rFE) is observed when isometric force following an active stretch is elevated compared to an isometric contraction at corresponding muscle lengths. Acute rFE has been confirmed in vivo in upper and lower limb muscles. However, it is uncertain whether rFE persists using multiple, consecutive contractions as per a training simulation. Using the knee flexors, 10 recreationally active participants (seven males, three females; age 31.00 years ± 8.43 years) performed baseline isometric contractions at 150° knee flexion (180° representing terminal knee extension) of 50% maximal voluntary activation of semitendinosus. Participants performed post-stretch isometric (PS-ISO) contractions (three sets of 10 repetitions) starting at 90° knee extension with a joint rotation of 60° at 60°·s-1 at 50% maximal voluntary activation of semitendinosus. Baseline isometric torque and muscle activation were compared to PS-ISO torque and muscle activation across all 30 repetitions. Significant rFE was noted in all repetitions (37.8-77.74%), with no difference in torque between repetitions or sets. There was no difference in activation of semitendinosus or biceps femoris long-head between baseline and PS-ISO contractions in all repetitions (ST; baseline ISO = 0.095-1.000 ± 0.036-0.039 Mv, PS-ISO = 0.094-0.098 ± 0.033-0.038 and BFlh; baseline ISO = 0.068-0.075 ± 0.031-0.038 Mv). This is the first investigation to observe rFE during multiple, consecutive submaximal PS-ISO contractions. PS-ISO contractions have the potential to be used as a training stimulus.
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Affiliation(s)
- Neil D. Chapman
- School of Health and Human Sciences, Southern Cross University, Lismore, NSW 2480, Australia; (J.W.W.); (S.B.); (Z.J.C.-M.); (R.M.)
- Faculty of Health Sciences and Medicine, Bond University, Robina, QLD 4229, Australia
| | - John W. Whitting
- School of Health and Human Sciences, Southern Cross University, Lismore, NSW 2480, Australia; (J.W.W.); (S.B.); (Z.J.C.-M.); (R.M.)
| | - Suzanne Broadbent
- School of Health and Human Sciences, Southern Cross University, Lismore, NSW 2480, Australia; (J.W.W.); (S.B.); (Z.J.C.-M.); (R.M.)
- School of Health and Behavioural Sciences, University of the Sunshine Coast, Sippy Downs, QLD 4556, Australia
| | - Zachary J. Crowley-McHattan
- School of Health and Human Sciences, Southern Cross University, Lismore, NSW 2480, Australia; (J.W.W.); (S.B.); (Z.J.C.-M.); (R.M.)
| | - Rudi Meir
- School of Health and Human Sciences, Southern Cross University, Lismore, NSW 2480, Australia; (J.W.W.); (S.B.); (Z.J.C.-M.); (R.M.)
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Power GA, Hinks A, Mashouri P, Contento VS, Chen J. The long and short of residual force enhancement non-responders. Eur J Appl Physiol 2020; 120:2565-2567. [DOI: 10.1007/s00421-020-04511-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Jakobi JM, Kuzyk SL, McNeil CJ, Dalton BH, Power GA. Motor unit contributions to activation reduction and torque steadiness following active lengthening: a study of residual torque enhancement. J Neurophysiol 2020; 123:2209-2216. [PMID: 32347154 DOI: 10.1152/jn.00394.2019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Following active lengthening, steady-state isometric (ISO) torque is greater than a purely ISO contraction at the same muscle length, this is referred to as residual torque enhancement (rTE). A phenomenon of rTE is activation reduction, characterized by reduced electromyography (EMG) amplitude for a given torque output. We hypothesized that lower motor unit discharge rates would contribute to activation reduction and lessening torque steadiness. Ten young male subjects performed ISO dorsiflexion contractions at 10 and 20% of maximal voluntary contraction (MVC) torque. During rTE trials, the muscle was activated at 10° of plantar flexion, then the ankle was rotated to the ISO position at 40°. Fine wire electrodes recorded motor unit (MU)-discharge rates and variability from the tibialis anterior. Surface EMG quantified activation reduction, and steadiness was determined as the coefficient of variation of torque. The activation reduction was 44 and 24% at 10 and 20% MVC, respectively (P < 0.05). Fewer MUs were recorded in the rTE than ISO condition at 10% (~47%) and 20% (~36%) MVC (P < 0.05). Discharge rates were 19 and 26% lower in the rTE compared with the ISO condition for 10 and 20% MVC, respectively (P < 0.05), with no difference in variability between conditions (P > 0.05). Steadiness was ~22 and 18% lower for the rTE than ISO condition at 10 and 20% MVC (P < 0.05). Our findings indicate that activation reduction may be attributed to lower MU discharge rate and fewer detectable MUs and that this theoretically contributes to a reduction in steadiness in the rTE condition.NEW & NOTEWORTHY Our findings indicate that lower electromyographic activity during the torque enhanced condition following active lengthening compared with a purely isometric contraction arises from fewer active motor units and a lower discharge rate of those that are active. We used an acute condition of increased torque capacity to induce a decrease in net output of the motor neuron pool during a submaximal task to demonstrate, in humans, the impact of motor unit activity on torque steadiness.
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Affiliation(s)
- Jennifer M Jakobi
- School of Health and Exercise Sciences, Faculty of Health and Social Development, University of British Columbia, Okanagan, British Columbia, Canada
| | - Samantha L Kuzyk
- School of Health and Exercise Sciences, Faculty of Health and Social Development, University of British Columbia, Okanagan, British Columbia, Canada
| | - Chris J McNeil
- School of Health and Exercise Sciences, Faculty of Health and Social Development, University of British Columbia, Okanagan, British Columbia, Canada
| | - Brian H Dalton
- School of Health and Exercise Sciences, Faculty of Health and Social Development, University of British Columbia, Okanagan, British Columbia, Canada
| | - Geoffrey A Power
- Department of Human Health and Nutritional Sciences, College of Biological Sciences, University of Guelph, Guelph, Ontario, Canada
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