1
|
Maas H, Noort W. Knee movements cause changes in the firing behaviour of muscle spindles located within the mono-articular ankle extensor soleus in the rat. Exp Physiol 2024; 109:125-134. [PMID: 36827200 PMCID: PMC10988709 DOI: 10.1113/ep090764] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 02/06/2023] [Indexed: 02/25/2023]
Abstract
We recently showed that within an intact muscle compartment, changing the length of one muscle affects the firing behaviour of muscle spindles located within a neighbouring muscle. The conditions tested, however, involved muscle lengths and relative positions that were beyond physiological ranges. The aim of the present study was to investigate the effects of simulated knee movements on the firing behaviour of muscle spindles located within rat soleus (SO) muscle. Firing from single muscle spindle afferents in SO was measured intra-axonally for different lengths (static) and during lengthening (dynamic) of the lateral gastrocnemius and plantaris muscles. Also, the location of the spindle within the muscle was assessed. Changing the length of synergistic ankle plantar flexors (simulating different static knee positions, between 45 and 130°) affected the force threshold, but not the length threshold, of SO muscle spindles. The effects on type II afferents were substantially (four times) higher than those on type IA afferents. Triangular stretch-shortening of synergistic muscles (simulating dynamic knee joint rotations of 15°) caused sudden changes in the firing rate of SO type IA and II afferents. Lengthening decreased and shortening increased the firing rate, independent of spindle location. This supports our prediction that the major point of application of forces exerted by connections between adjacent muscles is at the distal end of SO. We conclude that muscle spindles provide the CNS with information about the condition of adjacent joints that the muscle does not span.
Collapse
Affiliation(s)
- Huub Maas
- Department of Human Movement Sciences, Faculty of Behavioural and Movement SciencesVrije Universiteit AmsterdamAmsterdamThe Netherlands
- Amsterdam Movement SciencesAmsterdamThe Netherlands
| | - Wendy Noort
- Department of Human Movement Sciences, Faculty of Behavioural and Movement SciencesVrije Universiteit AmsterdamAmsterdamThe Netherlands
| |
Collapse
|
2
|
Mulla DM, Keir PJ. Neuromuscular control: from a biomechanist's perspective. Front Sports Act Living 2023; 5:1217009. [PMID: 37476161 PMCID: PMC10355330 DOI: 10.3389/fspor.2023.1217009] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 06/21/2023] [Indexed: 07/22/2023] Open
Abstract
Understanding neural control of movement necessitates a collaborative approach between many disciplines, including biomechanics, neuroscience, and motor control. Biomechanics grounds us to the laws of physics that our musculoskeletal system must obey. Neuroscience reveals the inner workings of our nervous system that functions to control our body. Motor control investigates the coordinated motor behaviours we display when interacting with our environment. The combined efforts across the many disciplines aimed at understanding human movement has resulted in a rich and rapidly growing body of literature overflowing with theories, models, and experimental paradigms. As a result, gathering knowledge and drawing connections between the overlapping but seemingly disparate fields can be an overwhelming endeavour. This review paper evolved as a need for us to learn of the diverse perspectives underlying current understanding of neuromuscular control. The purpose of our review paper is to integrate ideas from biomechanics, neuroscience, and motor control to better understand how we voluntarily control our muscles. As biomechanists, we approach this paper starting from a biomechanical modelling framework. We first define the theoretical solutions (i.e., muscle activity patterns) that an individual could feasibly use to complete a motor task. The theoretical solutions will be compared to experimental findings and reveal that individuals display structured muscle activity patterns that do not span the entire theoretical solution space. Prevalent neuromuscular control theories will be discussed in length, highlighting optimality, probabilistic principles, and neuromechanical constraints, that may guide individuals to families of muscle activity solutions within what is theoretically possible. Our intention is for this paper to serve as a primer for the neuromuscular control scientific community by introducing and integrating many of the ideas common across disciplines today, as well as inspire future work to improve the representation of neural control in biomechanical models.
Collapse
|
3
|
Javidi M, McGowan CP, Lin DC. Estimation of the force-velocity properties of individual muscles from measurement of the combined plantarflexor properties. J Exp Biol 2020; 223:jeb219980. [PMID: 32680898 DOI: 10.1242/jeb.219980] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 07/13/2020] [Indexed: 11/20/2022]
Abstract
The force-velocity (F-V) properties of isolated muscles or muscle fibers have been well studied in humans and other animals. However, determining properties of individual muscles in vivo remains a challenge because muscles usually function within a synergistic group. Modeling has been used to estimate the properties of an individual muscle from the experimental measurement of the muscle group properties. While this approach can be valuable, the models and the associated predictions are difficult to validate. In this study, we measured the in situ F-V properties of the maximally activated kangaroo rat plantarflexor group and used two different assumptions and associated models to estimate the properties of the individual plantarflexors. The first model (Mdl1) assumed that the percent contributions of individual muscles to group force and power were based upon the muscles' cross-sectional area and were constant across the different isotonic loads applied to the muscle group. The second model (Mdl2) assumed that the F-V properties of the fibers within each muscle were identical, but because of differences in muscle architecture, the muscles' contributions to the group properties changed with isotonic load. We compared the two model predictions with independent estimates of the muscles' contributions based upon sonomicrometry measurements of muscle length. We found that predictions from Mdl2 were not significantly different from sonomicrometry-based estimates while those from Mdl1 were significantly different. The results of this study show that incorporating appropriate fiber properties and muscle architecture is necessary to parse the individual muscles' contributions to the group F-V properties.
Collapse
Affiliation(s)
- Mehrdad Javidi
- Voiland School of Chemical Engineering and Bioengineering, Washington State University, PO Box 646515, Pullman, WA 99164, USA
| | - Craig P McGowan
- Department of Biological Sciences, University of Idaho, 875 Perimeter Drive, MS 3051, Moscow, ID 83844, USA
- WWAMI Medical Education Program, University of Idaho, 875 Perimeter Drive, MS 4207, Moscow, ID 83844, USA
- Washington Center for Muscle Biology, Washington State University, PO Box 646515, Pullman, WA 99164, USA
| | - David C Lin
- Voiland School of Chemical Engineering and Bioengineering, Washington State University, PO Box 646515, Pullman, WA 99164, USA
- Washington Center for Muscle Biology, Washington State University, PO Box 646515, Pullman, WA 99164, USA
- Department of Integrative Physiology and Neuroscience, Washington State University, PO Box 647620, Pullman, WA 99164, USA
| |
Collapse
|
4
|
Monte A, Maganaris C, Baltzopoulos V, Zamparo P. The influence of Achilles tendon mechanical behaviour on "apparent" efficiency during running at different speeds. Eur J Appl Physiol 2020; 120:2495-2505. [PMID: 32840697 PMCID: PMC7557501 DOI: 10.1007/s00421-020-04472-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 08/10/2020] [Indexed: 11/30/2022]
Abstract
Purpose We investigated the role of elastic strain energy on the “apparent” efficiency of locomotion (AE), a parameter that is known to increase as a function of running speed (up to 0.5–0.7) well above the values of “pure” muscle efficiency (about 0.25–0.30). Methods In vivo ultrasound measurements of the gastrocnemius medialis (GM) muscle–tendon unit (MTU) were combined with kinematic, kinetic and metabolic measurements to investigate the possible influence of the Achilles tendon mechanical behaviour on the mechanics (total mechanical work, WTOT) and energetics (net energy cost, Cnet) of running at different speeds (10, 13 and 16 km h−1); AE was calculated as WTOT/Cnet. Results GM fascicles shortened during the entire stance phase, the more so the higher the speed, but the majority of the MTU displacement was accommodated by the Achilles tendon. Tendon strain and recoil increased as a function of running speed (P < 0.01 and P < 0.001, respectively). The contribution of elastic energy to the positive work generated by the MTU also increased with speed (from 0.09 to 0.16 J kg−1 m−1). Significant negative correlations (P < 0.01) were observed between tendon work and metabolic energy at each running speed (the higher the tendon work the lower the metabolic demand) and significant positive correlations were observed between tendon work and AE (P < 0.001) at each running speed (the higher the tendon work the higher the efficiency). Conclusion These results support the notion that the dynamic function of tendons is integral in reducing energy expenditure and increasing the “apparent” efficiency of running.
Collapse
Affiliation(s)
- Andrea Monte
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, via Felice Casorati, 43, 37131, Verona, Italy
- Research Institute for Sport and Exercise Sciences (RISES), Liverpool John Moores University, Liverpool, UK
| | - Constantinos Maganaris
- Research Institute for Sport and Exercise Sciences (RISES), Liverpool John Moores University, Liverpool, UK
| | - Vasilios Baltzopoulos
- Research Institute for Sport and Exercise Sciences (RISES), Liverpool John Moores University, Liverpool, UK
| | - Paola Zamparo
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, via Felice Casorati, 43, 37131, Verona, Italy.
| |
Collapse
|
5
|
Monte A, Baltzopoulos V, Maganaris CN, Zamparo P. Gastrocnemius Medialis and Vastus Lateralis in vivo muscle‐tendon behavior during running at increasing speeds. Scand J Med Sci Sports 2020; 30:1163-1176. [DOI: 10.1111/sms.13662] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 02/20/2020] [Accepted: 03/18/2020] [Indexed: 11/28/2022]
Affiliation(s)
- Andrea Monte
- Department of Neurosciences, Biomedicine and Movement Sciences University of Verona Verona Italy
- Research Institute for Sport and Exercise Sciences (RISES) Liverpool John Moores University Liverpool UK
| | - Vasilios Baltzopoulos
- Research Institute for Sport and Exercise Sciences (RISES) Liverpool John Moores University Liverpool UK
| | - Constantinos N. Maganaris
- Research Institute for Sport and Exercise Sciences (RISES) Liverpool John Moores University Liverpool UK
| | - Paola Zamparo
- Department of Neurosciences, Biomedicine and Movement Sciences University of Verona Verona Italy
| |
Collapse
|
6
|
Javidi M, McGowan CP, Lin DC. The Contributions of Individual Muscle–Tendon Units to the Plantarflexor Group Force–Length Properties. Ann Biomed Eng 2019; 47:2168-2177. [DOI: 10.1007/s10439-019-02288-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 05/09/2019] [Indexed: 11/24/2022]
|
7
|
Maas H. Significance of epimuscular myofascial force transmission under passive muscle conditions. J Appl Physiol (1985) 2019; 126:1465-1473. [DOI: 10.1152/japplphysiol.00631.2018] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In the past 20 yr, force transmission via connective tissue linkages at the muscle belly surface, called epimuscular myofascial force transmission, has been studied extensively. In this article, the effects of epimuscular linkages under passive muscle conditions are reviewed. Several animal studies that included direct (invasive) measurements of force transmission have shown that different connective tissue structures serve as an epimuscular pathway and that these tissues have sufficient stiffness, especially at supraphysiological muscle lengths and relative positions, to transmit substantial passive forces (up to 15% of active optimal force). Exact values of lumped tissue stiffness for different connective tissue structures have not yet been estimated. Experiments using various imaging techniques (ultrasound, MRI, shear wave elastography) have yielded some, but weak, evidence of epimuscular myofascial force transmission for passive muscles in humans. At this point, the functional consequences of epimuscular pathways for muscle and joint mechanics in the intact body are still unknown. Potentially, however, these pathways may affect sensory feedback and, thereby, neuromuscular control. In addition, altered epimuscular force transmission in pathological conditions may also contribute to changes in passive range of joint motion.
Collapse
Affiliation(s)
- Huub Maas
- Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam Movement Sciences, Amsterdam, The Netherlands
| |
Collapse
|
8
|
Diong J, Héroux ME, Gandevia SC, Herbert RD. Minimal force transmission between human thumb and index finger muscles under passive conditions. PLoS One 2019; 14:e0212496. [PMID: 30768639 PMCID: PMC6377133 DOI: 10.1371/journal.pone.0212496] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 02/04/2019] [Indexed: 11/17/2022] Open
Abstract
It has been hypothesized that force can be transmitted between adjacent muscles. Intermuscle force transmission violates the assumption that muscles act in mechanical isolation, and implies that predictions from biomechanical models are in error due to mechanical interactions between muscles, but the functional relevance of intermuscle force transmission is unclear. To investigate intermuscle force transmission between human flexor pollicis longus and the index finger part of flexor digitorum profundus, we compared finger flexion force produced by passive thumb flexion after one of three conditioning protocols: passive thumb flexion-extension cycling, thumb flexion maximal voluntary contraction (MVC), and thumb extension stretch. Finger flexion force increased after all three conditions. Compared to passive thumb flexion-extension cycling, change in finger flexion force was less after thumb extension stretch (mean difference 0.028 N, 95% CI 0.005 to 0.051 N), but not after thumb flexion MVC (0.007 N, 95% CI -0.020 to 0.033 N). As muscle conditioning changed finger flexion force produced by passive thumb flexion, the change in force is likely due to intermuscle force transmission. Thus, intermuscle force transmission resulting from passive stretch of an adjacent muscle is probably small enough to be ignored.
Collapse
Affiliation(s)
- Joanna Diong
- School of Medical Sciences, Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia.,Neuroscience Research Australia (NeuRA), Randwick, NSW, Australia
| | - Martin E Héroux
- Neuroscience Research Australia (NeuRA), Randwick, NSW, Australia.,University of New South Wales, Randwick, NSW, Australia
| | - Simon C Gandevia
- Neuroscience Research Australia (NeuRA), Randwick, NSW, Australia.,University of New South Wales, Randwick, NSW, Australia
| | - Robert D Herbert
- Neuroscience Research Australia (NeuRA), Randwick, NSW, Australia.,University of New South Wales, Randwick, NSW, Australia
| |
Collapse
|
9
|
Tijs C, Bernabei M, van Dieën JH, Maas H. Myofascial Loads Can Occur without Fascicle Length Changes. Integr Comp Biol 2019; 58:251-260. [PMID: 29873725 DOI: 10.1093/icb/icy049] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Many studies have shown that connective tissue linkages can transmit force between synergistic muscles and that such force transmission depends on the position of these muscles relative to each other and on properties of their intermuscular connective tissues. Moving neighboring muscles has been reported to cause longitudinal deformations within passive muscles held at a constant muscle-tendon unit (MTU) length (e.g., soleus [SO]), but muscle forces were not directly measured. Deformations do not provide a direct measure of the force transmitted between muscles. We combined two different muscle preparations to assess whether myofascial loads exerted by neighboring muscles result in length changes of SO fascicles. We investigated the effects of proximal MTU length changes of two-joint gastrocnemius (GA) and plantaris (PL) muscles on the fascicle length of the one-joint SO muscle within (1) an intact muscle compartment and (2) a disrupted compartment that allowed measurements of fascicle length and distal tendon force of SO simultaneously. SO muscle bellies of Wistar rats (n = 5) were implanted with sonomicrometry crystals. In three animals, connectivity between SO and GA+PL was enhanced. Measurements were performed before and during maximal excitation of all plantar flexor muscles. In both setups, MTU length of GA+PL did not affect the length of SO fascicles, neither during passive nor active conditions. However, lengthening the MTU of GA+PL increased distal tendon force of SO by 43.3-97.8% (P < 0.001) and 27.5-182.6% (P < 0.001), respectively. This indicates that substantial myofascial force transmission between SO and synergistic muscle can occur via a connective tissue network running parallel to the series of SO sarcomeres without substantial length changes of SO fascicles.
Collapse
Affiliation(s)
- Chris Tijs
- Department of Organismic and Evolutionary Biology, Concord Field Station-Harvard University, Bedford, MA 01730, USA
| | - Michel Bernabei
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60208, USA
| | - Jaap H van Dieën
- Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, 1081 BT, Amsterdam, The Netherlands
| | - Huub Maas
- Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, 1081 BT, Amsterdam, The Netherlands
| |
Collapse
|
10
|
de Brito Fontana H, de Campos D, Sawatsky A, Han SW, Herzog W. Why do muscles lose torque potential when activated within their agonistic group? J Exp Biol 2019; 223:jeb.213843. [DOI: 10.1242/jeb.213843] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 11/26/2019] [Indexed: 11/20/2022]
Abstract
Agonistic muscles lose approximately 20% of their individual torque generating capacity when activated with their agonistic muscles compared to when stimulated in isolation. In this study, we (i) tested if this loss in torque was accompanied by a corresponding loss in force, thereby testing the potential role of changes in moment arms between conditions; (ii) removed all inter-muscular connections between the quadriceps muscles, thus determining the potential role of inter-muscular force transmission; and (iii) systematically changed the inter-muscular pressure by performing experiments at different activation/force levels, thereby exploring the possible role of inter-muscular pressure in the loss of torque capacity with simultaneous muscle activation. Experiments were performed in a New Zealand White rabbit quadriceps model (n=5). Torque and force were measured during activation of femoral nerve branches that supply the individual quadriceps muscles while activating these branches simultaneously and in isolation. Regardless of joint angle and inter-muscular connections between muscles, the differences in torque values between the simultaneous and the isolated activation of the quadriceps muscles were also observed for the directly measured force values. Mean differences in simultaneous and isolated muscle activation remained similar between the intact and separated conditions: torque difference (21±5% of maximum isometric torque of intact condition [MICtorque], versus 19±6% MICtorque respectively) and for force (18±3% MICforce versus 19±7% MICforce respectively). The absolute torque loss was independent of the force, and thus presumably the inter-muscular pressures. Based on these results, we conclude that neither moment arm, inter-muscular pressure nor inter-muscular force transmission seems to be the primary cause for the torque deficit observed during simultaneous compared to isolated muscle activation. The mechanisms underlying loss of force capacity during agonistic muscle contraction remain unknown.
Collapse
Affiliation(s)
- Heiliane de Brito Fontana
- Department of Morphological Sciences, School of Biological Sciences, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil
| | - Daiani de Campos
- Biomechanics Laboratory, School of Sport Sciences, Federal University of Santa Catarina, Florianópolis, Santa Catarina, Brazil
| | - Andrew Sawatsky
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
| | - Seong-won Han
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
| | - Walter Herzog
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
| |
Collapse
|
11
|
Lai AKM, Lichtwark GA, Schache AG, Pandy MG. Differences in in vivo muscle fascicle and tendinous tissue behavior between the ankle plantarflexors during running. Scand J Med Sci Sports 2018; 28:1828-1836. [DOI: 10.1111/sms.13089] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/15/2018] [Indexed: 01/09/2023]
Affiliation(s)
- A. K. M. Lai
- Department of Biomedical Physiology and Kinesiology Simon Fraser University Burnaby BC Canada
| | - G. A. Lichtwark
- Centre for Sensorimotor Performance The School of Human Movement Studies The University of Queensland St Lucia QLD Australia
| | - A. G. Schache
- Department of Mechanical Engineering University of Melbourne Parkville VIC Australia
| | - M. G. Pandy
- Department of Mechanical Engineering University of Melbourne Parkville VIC Australia
| |
Collapse
|
12
|
Passive stiffness of monoarticular lower leg muscles is influenced by knee joint angle. Eur J Appl Physiol 2018; 118:585-593. [DOI: 10.1007/s00421-018-3798-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 12/24/2017] [Indexed: 10/18/2022]
|
13
|
Wilke J, Schleip R, Yucesoy CA, Banzer W. Not merely a protective packing organ? A review of fascia and its force transmission capacity. J Appl Physiol (1985) 2018; 124:234-244. [DOI: 10.1152/japplphysiol.00565.2017] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Recent research indicates that fascia is capable of changing its biomechanical properties. Moreover, as it links the skeletal muscles, forming a body-wide network of multidirectional myofascial continuity, the classical conception of muscles as independent actuators has been challenged. Hence, the present synthesis review aims to characterize the mechanical relevance of the connective tissue for the locomotor system. Results of cadaveric and animal studies suggest a clinically relevant myofascial force transmission to neighboring structures within one limb (e.g., between synergists) and in the course of muscle-fascia chains (e.g., between leg and trunk). Initial in vivo trials appear to underpin these findings, demonstrating the existence of nonlocal exercise effects. However, the factors influencing the amount of transmitted force (e.g., age and physical activity) remain controversial, as well as the role of the central nervous system within the context of the observed remote exercise effects.
Collapse
Affiliation(s)
- Jan Wilke
- Department of Sports Medicine, Goethe University, Frankfurt am Main, Germany
| | - Robert Schleip
- Fascia Research Group, Neurosurgical Clinic Guenzburg of Ulm University, Ulm, Germany
| | - Can A. Yucesoy
- Institute of Biomedical Engineering, Bogazici University, Instanbul, Turkey
| | - Winfried Banzer
- Department of Sports Medicine, Goethe University, Frankfurt am Main, Germany
| |
Collapse
|
14
|
Kaya CS, Temelli Y, Ates F, Yucesoy CA. Effects of inter-synergistic mechanical interactions on the mechanical behaviour of activated spastic semitendinosus muscle of patients with cerebral palsy. J Mech Behav Biomed Mater 2018; 77:78-84. [DOI: 10.1016/j.jmbbm.2017.08.040] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Revised: 08/21/2017] [Accepted: 08/25/2017] [Indexed: 11/26/2022]
|
15
|
Marinho HVR, Amaral GM, Moreira BS, Santos TRT, Magalhães FA, Souza TR, Fonseca ST. Myofascial force transmission in the lower limb: An in vivo experiment. J Biomech 2017; 63:55-60. [DOI: 10.1016/j.jbiomech.2017.07.026] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 07/25/2017] [Accepted: 07/29/2017] [Indexed: 01/26/2023]
|
16
|
Bernabei M, van Dieën JH, Maas H. Evidence of adaptations of locomotor neural drive in response to enhanced intermuscular connectivity between the triceps surae muscles of the rat. J Neurophysiol 2017; 118:1677-1689. [PMID: 28490645 DOI: 10.1152/jn.00625.2016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 05/08/2017] [Accepted: 05/08/2017] [Indexed: 01/13/2023] Open
Abstract
The aims of this study were to investigate changes 1) in the coordination of activation of the triceps surae muscle group, and 2) in muscle belly length of soleus (SO) and lateral gastrocnemius (LG) during locomotion (trotting) in response to increased stiffness of intermuscular connective tissues in the rat. We measured muscle activation and muscle belly lengths, as well as hindlimb kinematics, before and after an artificial enhancement of the connectivity between SO and LG muscles obtained by implanting a tissue-integrating surgical mesh at the muscles' interface. We found that SO muscle activation decreased to 62%, while activation of LG and medial gastrocnemius muscles increased to 134 and 125%, respectively, compared with the levels measured preintervention. Although secondary additional or amplified activation bursts were observed with enhanced connectivity, the primary pattern of activation over the stride and the burst duration were not affected by the intervention. Similar muscle length changes after manipulation were observed, suggesting that length feedback from spindle receptors within SO and LG was not affected by the connectivity enhancement. We conclude that peripheral mechanical constraints given by morphological (re)organization of connective tissues linking synergists are taken into account by the central nervous system. The observed shift in activity toward the gastrocnemius muscles after the intervention suggests that these larger muscles are preferentially recruited when the soleus has a similar mechanical disadvantage in that it produces an unwanted flexion moment around the knee.NEW & NOTEWORTHY Connective tissue linkages between muscle-tendon units may act as an additional mechanical constraint on the musculoskeletal system, thereby reducing the spectrum of solutions for performing a motor task. We found that intermuscular coordination changes following intermuscular connectivity enhancement. Besides showing that the extent of such connectivity is taken into account by the central nervous system, our results suggest that recruitment of triceps surae muscles is governed by the moments produced at the ankle-knee joints.
Collapse
Affiliation(s)
- Michel Bernabei
- Department of Human Movement Sciences, Faculty of Behavioral and Movement Sciences, Vrije Universiteit Amsterdam, MOVE Research Institute Amsterdam, The Netherlands
| | - Jaap H van Dieën
- Department of Human Movement Sciences, Faculty of Behavioral and Movement Sciences, Vrije Universiteit Amsterdam, MOVE Research Institute Amsterdam, The Netherlands
| | - Huub Maas
- Department of Human Movement Sciences, Faculty of Behavioral and Movement Sciences, Vrije Universiteit Amsterdam, MOVE Research Institute Amsterdam, The Netherlands
| |
Collapse
|
17
|
Bernabei M, van Dieën JH, Maas H. Longitudinal and transversal displacements between triceps surae muscles during locomotion of the rat. J Exp Biol 2017; 220:537-550. [DOI: 10.1242/jeb.143545] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 11/17/2016] [Indexed: 11/20/2022]
Abstract
ABSTRACT
The functional consequences of differential muscle activation and contractile behavior between mechanically coupled synergists are still poorly understood. Even though synergistic muscles exert similar mechanical effects at the joint they span, differences in the anatomy, morphology and neural drive may lead to non-uniform contractile conditions. This study aimed to investigate the patterns of activation and contractile behavior of triceps surae muscles, to understand how these contribute to the relative displacement between the one-joint soleus (SO) and two-joint lateral gastrocnemius (LG) muscle bellies and their distal tendons during locomotion in the rat. In seven rats, muscle belly lengths and muscle activation during level and upslope trotting were measured by sonomicrometry crystals and electromyographic electrodes chronically implanted in the SO and LG. Length changes of muscle–tendon units (MTUs) and tendon fascicles were estimated based on joint kinematics and muscle belly lengths. Distances between implanted crystals were further used to assess longitudinal and transversal deformations of the intermuscular volume between the SO and LG. For both slope conditions, we observed differential timing of muscle activation as well as substantial differences in contraction speeds between muscle bellies (maximal relative speed 55.9 mm s−1). Muscle lengths and velocities did not differ significantly between level and upslope locomotion, only EMG amplitude of the LG was affected by slope. Relative displacements between SO and LG MTUs were found in both longitudinal and transversal directions, yielding an estimated maximal length change difference of 2.0 mm between their distal tendons. Such relative displacements may have implications for the force exchanged via intermuscular and intertendinous pathways.
Collapse
Affiliation(s)
- Michel Bernabei
- Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, MOVE Research Institute Amsterdam, Amsterdam 1081, The Netherlands
| | - Jaap H. van Dieën
- Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, MOVE Research Institute Amsterdam, Amsterdam 1081, The Netherlands
| | - Huub Maas
- Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, MOVE Research Institute Amsterdam, Amsterdam 1081, The Netherlands
| |
Collapse
|
18
|
Tijs C, van Dieën JH, Baan GC, Maas H. Synergistic Co-activation Increases the Extent of Mechanical Interaction between Rat Ankle Plantar-Flexors. Front Physiol 2016; 7:414. [PMID: 27708589 PMCID: PMC5030264 DOI: 10.3389/fphys.2016.00414] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2016] [Accepted: 09/05/2016] [Indexed: 11/18/2022] Open
Abstract
Force transmission between rat ankle plantar-flexors has been found for physiological muscle lengths and relative positions, but only with all muscles maximally activated. The aims of this study were to assess intermuscular mechanical interactions between ankle plantar-flexors during (i) fully passive conditions, (ii) excitation of soleus (SO), (iii) excitation of lateral gastrocnemius (LG), and (iv) during co-activation of SO, and LG (SO&LG). We assessed effects of proximal lengthening of LG and plantaris (PL) muscles (i.e., simulating knee extension) on forces exerted at the distal SO tendon (FSO) and on the force difference between the proximal and distal LG+PL tendons (ΔFLG+PL) of the rat. LG+PL lengthening increased FSO to a larger extent (p = 0.017) during LG excitation (0.0026 N/mm) than during fully passive conditions (0.0009 N/mm). Changes in FSO in response to LG+PL lengthening were lower (p = 0.002) during SO only excitation (0.0056 N/mm) than during SO&LG excitation (0.0101 N/mm). LG+PL lengthening changed ΔFLG+PL to a larger extent (p = 0.007) during SO excitation (0.0211 N/mm) than during fully passive conditions (0.0157 N/mm). In contrast, changes in ΔFLG+PL in response to LG+PL lengthening during LG excitation (0.0331 N/mm) were similar (p = 0.161) to that during SO&LG excitation (0.0370 N/mm). In all conditions, changes of FSO were lower than those of ΔFLG+PL. This indicates that muscle forces were transmitted not only between LG+PL and SO, but also between LG+PL and other surrounding structures. In addition, epimuscular myofascial force transmission between rat ankle plantar-flexors was enhanced by muscle activation. However, the magnitude of this interaction was limited.
Collapse
Affiliation(s)
- Chris Tijs
- Department of Human Movement Sciences, Faculty of Behavioral and Movement Sciences, MOVE Research Institute Amsterdam, Vrije Universiteit AmsterdamAmsterdam, Netherlands; Department of Organismic and Evolutionary Biology, Harvard UniversityCambridge, MA, USA
| | - Jaap H van Dieën
- Department of Human Movement Sciences, Faculty of Behavioral and Movement Sciences, MOVE Research Institute Amsterdam, Vrije Universiteit Amsterdam Amsterdam, Netherlands
| | - Guus C Baan
- Department of Human Movement Sciences, Faculty of Behavioral and Movement Sciences, MOVE Research Institute Amsterdam, Vrije Universiteit Amsterdam Amsterdam, Netherlands
| | - Huub Maas
- Department of Human Movement Sciences, Faculty of Behavioral and Movement Sciences, MOVE Research Institute Amsterdam, Vrije Universiteit Amsterdam Amsterdam, Netherlands
| |
Collapse
|
19
|
Tijs C, van Dieën JH, Maas H. Limited mechanical effects of intermuscular myofascial connections within the intact rat anterior crural compartment. J Biomech 2016; 49:2953-2959. [PMID: 27452876 DOI: 10.1016/j.jbiomech.2016.07.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Revised: 07/07/2016] [Accepted: 07/08/2016] [Indexed: 01/28/2023]
Abstract
Skeletal muscles of the rat anterior crural compartment are mechanically connected by epimuscular myofascial connections, but the relevance for mechanical muscle function within physiological ranges of joint motion is unclear. We evaluated the net effect at the ankle joint of epimuscular myofascial connections between tibialis anterior (TA) and extensor digitorum longus (EDL) muscles in the rat (n=8) and determined which anatomical structures may mediate such epimuscular mechanical interactions. We assessed (1) effects of knee angle (i.e. changes in EDL length and position relative to TA) and interactions of knee angle with fasciotomy and proximal EDL tenotomy on TA ankle moment and (2) the effect of knee angle on TA and EDL ankle moment summation. Knee angle was varied between 60° and 130°. Ankle angle was kept constant (90°). TA and EDL were excited individually and simultaneously (TA&EDL). The mathematical sum of individual TA and EDL moments was compared with the moment exerted by TA&EDL to assess the extent of non-additive ankle moment summation. Magnitude of TA ankle moment was not affected by knee angle, but frontal plane moment direction was. However, dissections indicated that this was not caused by the compartmental fascia or EDL length changes. Moment summation was non-additive in magnitude (+1.1±1.1% mean±s.d.) and frontal plane direction. The latter was affected by knee angle and ranged from +0.2±0.3° at 60° to +1.1±0.6° at 130°. As the net effects found were very limited, we conclude that myofascial connections between muscles in the anterior crural compartment have limited mechanical relevance during normal movement.
Collapse
Affiliation(s)
- Chris Tijs
- Department of Human Movement Sciences, Faculty of Behaviour and Movement Sciences, Vrije Universiteit Amsterdam, MOVE Research Institute Amsterdam, The Netherlands
| | - Jaap H van Dieën
- Department of Human Movement Sciences, Faculty of Behaviour and Movement Sciences, Vrije Universiteit Amsterdam, MOVE Research Institute Amsterdam, The Netherlands
| | - Huub Maas
- Department of Human Movement Sciences, Faculty of Behaviour and Movement Sciences, Vrije Universiteit Amsterdam, MOVE Research Institute Amsterdam, The Netherlands.
| |
Collapse
|
20
|
Bernabei M, Maas H, van Dieën JH. A lumped stiffness model of intermuscular and extramuscular myofascial pathways of force transmission. Biomech Model Mechanobiol 2016; 15:1747-1763. [PMID: 27193153 PMCID: PMC5106516 DOI: 10.1007/s10237-016-0795-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 05/03/2016] [Indexed: 12/02/2022]
Abstract
Mechanical behavior of skeletal muscles is commonly modeled under the assumption of mechanical independence between individual muscles within a muscle group. Epimuscular myofascial force transmission via the connective tissue network surrounding a muscle challenges this assumption as it alters the force distributed to the tendons of individual muscles. This study aimed to derive a lumped estimate of stiffness of the intermuscular and extramuscular connective tissues and to assess changes in such stiffness in response to a manipulation of the interface between adjacent muscles. Based on in situ measurements of force transmission in the rat plantar flexors, before and after resection of their connective tissue network, a nonlinear estimate of epimuscular myofascial stiffness was quantified and included in a multi-muscle model with lumped parameters which allows for force transmission depending on the relative position between the muscles in the group. Such stiffness estimate was assessed for a group with normal intermuscular connective tissues and for a group with increased connectivity, mimicking scar tissue development. The model was able to successfully predict the amount of epimuscular force transmission for different experimental conditions than those used to obtain the model parameters. The proposed nonlinear stiffness estimates of epimuscular pathways could be integrated in larger musculoskeletal models, to provide more accurate predictions of force when effects of mechanical interaction or altered epimuscular connections, e.g. after surgery or injury, are substantial.
Collapse
Affiliation(s)
- Michel Bernabei
- Department of Human Movement Sciences, Vrije Universiteit Amsterdam, MOVE Research Institute Amsterdam, Van der Boechorststraat 9, 1081, Amsterdam, The Netherlands
| | - Huub Maas
- Department of Human Movement Sciences, Vrije Universiteit Amsterdam, MOVE Research Institute Amsterdam, Van der Boechorststraat 9, 1081, Amsterdam, The Netherlands.
| | - Jaap H van Dieën
- Department of Human Movement Sciences, Vrije Universiteit Amsterdam, MOVE Research Institute Amsterdam, Van der Boechorststraat 9, 1081, Amsterdam, The Netherlands
| |
Collapse
|
21
|
Smilde HA, Vincent JA, Baan GC, Nardelli P, Lodder JC, Mansvelder HD, Cope TC, Maas H. Changes in muscle spindle firing in response to length changes of neighboring muscles. J Neurophysiol 2016; 115:3146-55. [PMID: 27075540 DOI: 10.1152/jn.00937.2015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 04/05/2016] [Indexed: 01/03/2023] Open
Abstract
Skeletal muscle force can be transmitted to the skeleton, not only via its tendons of origin and insertion but also through connective tissues linking the muscle belly to surrounding structures. Through such epimuscular myofascial connections, length changes of a muscle may cause length changes within an adjacent muscle and hence, affect muscle spindles. The aim of the present study was to investigate the effects of epimuscular myofascial forces on feedback from muscle spindles in triceps surae muscles of the rat. We hypothesized that within an intact muscle compartment, muscle spindles not only signal length changes of the muscle in which they are located but can also sense length changes that occur as a result of changing the length of synergistic muscles. Action potentials from single afferents were measured intra-axonally in response to ramp-hold release (RHR) stretches of an agonistic muscle at different lengths of its synergist, as well as in response to synergist RHRs. A decrease in force threshold was found for both soleus (SO) and lateral gastrocnemius afferents, along with an increase in length threshold for SO afferents. In addition, muscle spindle firing could be evoked by RHRs of the synergistic muscle. We conclude that muscle spindles not only signal length changes of the muscle in which they are located but also local length changes that occur as a result of changing the length and relative position of synergistic muscles.
Collapse
Affiliation(s)
- Hiltsje A Smilde
- Department of Human Movement Sciences, MOVE Research Institute Amsterdam, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands; Department of Neuroscience, Cell Biology and Physiology, Wright State University, Dayton, Ohio
| | - Jake A Vincent
- Department of Neuroscience, Cell Biology and Physiology, Wright State University, Dayton, Ohio
| | - Guus C Baan
- Department of Human Movement Sciences, MOVE Research Institute Amsterdam, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Paul Nardelli
- Department of Neuroscience, Cell Biology and Physiology, Wright State University, Dayton, Ohio; School of Applied Physiology and Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia; and
| | - Johannes C Lodder
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Huibert D Mansvelder
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Tim C Cope
- Department of Neuroscience, Cell Biology and Physiology, Wright State University, Dayton, Ohio; School of Applied Physiology and Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia; and
| | - Huub Maas
- Department of Human Movement Sciences, MOVE Research Institute Amsterdam, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands;
| |
Collapse
|
22
|
Siebert T, Rode C, Till O, Stutzig N, Blickhan R. Force reduction induced by unidirectional transversal muscle loading is independent of local pressure. J Biomech 2016; 49:1156-1161. [PMID: 26976226 DOI: 10.1016/j.jbiomech.2016.02.053] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Revised: 02/19/2016] [Accepted: 02/29/2016] [Indexed: 10/22/2022]
Abstract
Transversal unidirectional compression applied to muscles via external loading affects muscle contraction dynamics in the longitudinal direction. A recent study reported decreasing longitudinal muscle forces with increasing transversal load applied with a constant contact area (i.e., leading to a simultaneous increase in local pressure). To shed light on these results, we examine whether the decrease in longitudinal force depends on the load, the local pressure, or both. To this end, we perform isometric experiments on rat M. gastrocnemius medialis without and with transversal loading (i) changing the local pressure from 1.1-3.2Ncm(-2) (n=9) at a constant transversal load (1.62N) and (ii) increasing the transversal load (1.15-3.45N) at a constant local pressure of 2.3Ncm(-2) (n=7). While we did not note changes in the decrease in longitudinal muscle force in the first experiment, the second experiment resulted in an almost-linear reduction of longitudinal force between 7.5±0.6% and 14.1±1.7%. We conclude that the observed longitudinal force reduction is not induced by local effects such as malfunction of single muscle compartments, but that similar internal stress conditions and myofilament configurations occur when the local pressure changes given a constant load. The decreased longitudinal force may be explained by increased internal pressure and a deformed myofilament lattice that is likely associated with the decomposition of cross-bridge forces on the one hand and the inhibition of cross-bridges on the other hand.
Collapse
Affiliation(s)
- Tobias Siebert
- Institute of Sport and Motion Science, University of Stuttgart, Stuttgart, Germany.
| | - Christian Rode
- Department of Motion Science, Friedrich-Schiller University Jena, Jena, Germany
| | - Olaf Till
- Department of Motion Science, Friedrich-Schiller University Jena, Jena, Germany
| | - Norman Stutzig
- Institute of Sport and Motion Science, University of Stuttgart, Stuttgart, Germany
| | - Reinhard Blickhan
- Department of Motion Science, Friedrich-Schiller University Jena, Jena, Germany
| |
Collapse
|
23
|
Unexpected Fascicle Length Changes In Denervated Feline Soleus Muscle During Stance Phase Of Walking. Sci Rep 2015; 5:17619. [PMID: 26635206 PMCID: PMC4669439 DOI: 10.1038/srep17619] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 11/03/2015] [Indexed: 11/27/2022] Open
Abstract
After surgical repair of traumatically severed peripheral nerves, associated muscles are paralyzed for weeks. Little is known about fascicle length changes in paralyzed muscles during locomotion. The aim of this study was to investigate to what extent, if any, muscle fascicles of denervated feline soleus (SO) change length during stance of walking when intact SO synergists are actively contracting. Hindlimb kinematics, SO fascicle and muscle-tendon unit (MTU) length, and EMG activity of SO, lateral gastrocnemius (LG) and medial gastrocnemius (MG) were measured during level and slope walking in adult cats. Measurements were taken before and 1–2 weeks following SO-LG denervation. Unexpectedly, SO fascicle lengthening and shortening during stance in all walking conditions were evident after denervation. The greatest SO fascicle shortening (17.3 ± 2.2% of a reference length) and least fascicle lengthening (1.5 ± 0.8%) after denervation were found during upslope walking, where MG EMG activity was greatest across slopes (P < 0.05) and greatest discrepancies between post denervation SO fascicle and MTU length changes occurred. These findings suggest that myofascial linkages between denervated SO and its active synergists might affect its fascicle length changes. Further studies are needed to directly test this suggestion.
Collapse
|
24
|
Tijs C, van Dieën JH, Maas H. Effects of epimuscular myofascial force transmission on sarcomere length of passive muscles in the rat hindlimb. Physiol Rep 2015; 3:3/11/e12608. [PMID: 26537346 PMCID: PMC4673637 DOI: 10.14814/phy2.12608] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Results from imaging studies and finite element models suggest epimuscular myofascial effects on sarcomere lengths in series within muscle fibers. However, experimental evidence is lacking. We evaluated epimuscular myofascial effects on (1) muscle belly, fiber, and mean sarcomere length and (2) sarcomere length distribution within passive fibers of the rat tibialis anterior (TA) and soleus (SO) muscles. Hindlimbs (n = 24) were positioned in predefined knee (55°, 90°, 125°, 160°) and ankle (either 90° or 125°) angles, and fixed in a formaldehyde solution. Varying knee joint angle causes changes in muscle–tendon unit length of SO and TA’s synergists, but not of SO and TA. Whole fibers were taken from SO and TA and photographed along their length. Mean sarcomere length was assessed for the entire fiber and for the proximal, intermediate, and distal thirds (fiber segments) separately. Mean sarcomere length of the fiber was not affected by knee angle, neither for SO (mean: 2.44 ± 0.03 μm and 2.19 ± 0.05 μm for ankle angles of 90° and 125°, respectively) nor for TA (mean: 2.33 ± 0.05 μm and 2.51 ± 0.07 μm for ankle angle set to 90° and 125°, respectively). Only for TA, a significant interaction between knee angle and fiber segment was found, indicating changes in the distribution of lengths of in-series sarcomeres. Thus, while epimuscular myofascial force transmission did not cause mean sarcomere length changes within passive SO and TA, it did alter the length distribution of sarcomeres within passive TA.
Collapse
Affiliation(s)
- Chris Tijs
- Department of Human Movement Sciences, Faculty of Behaviour and Movement Sciences, Vrije Universiteit Amsterdam, MOVE Research Institute Amsterdam, The Netherlands
| | - Jaap H van Dieën
- Department of Human Movement Sciences, Faculty of Behaviour and Movement Sciences, Vrije Universiteit Amsterdam, MOVE Research Institute Amsterdam, The Netherlands
| | - Huub Maas
- Department of Human Movement Sciences, Faculty of Behaviour and Movement Sciences, Vrije Universiteit Amsterdam, MOVE Research Institute Amsterdam, The Netherlands
| |
Collapse
|