The identification of extensive samples of motor units in human muscles reveals diverse effects of neuromodulatory inputs on the rate coding DOI Open Access
Simon Avrillon, François Hug, Roger M. Enoka

et al.

Published: Nov. 21, 2024

Movements are performed by motoneurons transforming synaptic inputs into an activation signal that controls muscle force. The control emerges from interactions between ionotropic and neuromodulatory to motoneurons. Critically, these vary across motoneuron pools differ muscles. To provide the most comprehensive framework date of motor unit activity during isometric contractions, we identified firing extensive samples units in Tibialis Anterior (129±44 per participant; n=8) Vastus Lateralis (130±63 muscles contractions up 80% maximal From this unique dataset, rate coding each was characterised as relation its instantaneous applied force, with assumption linear increase force reflects a proportional net excitatory received motoneuron. This natural logarithm function comprised two stages. initial stage marked steep acceleration rate, which greater for low- than medium- high-threshold units. second high- low-threshold Changes were largely non-linear ramp-up ramp-down phases task, but significant prolonged only evident medium-threshold Contrary what is usually assumed, our results demonstrate can follow large variety trends pool. neural perspective, findings indicate how use gain transform limited bandwidths intended

Language: Английский

Integrating muscle energetics into biomechanical models to understand variance in the cost of movement DOI
Glen A. Lichtwark, Luke N. Jessup, Ryan N. Konno

et al.

Journal of Experimental Biology, Journal Year: 2025, Volume and Issue: 228(Suppl_1)

Published: Feb. 15, 2025

ABSTRACT In this Review, we explore the state of art biomechanical models for estimating energy consumption during terrestrial locomotion. We consider different mechanical that provide a solid framework to understand movement energetics from perspective force and work requirements. Whilst such are highly informative, they lack specificity predicting absolute metabolic rates across range species or variations in patterns. Muscles consume when activate generate tension, as well shorten positive work. Phenomenological muscle incorporating steady-state parameters have been developed able reproduce how fibre changes under contractile conditions; however, difficult validate scaled up whole muscle. This is, part, owing limited availability data relate dynamics energetic contraction large mammalian muscles. Furthermore, factors including compliance tendinous tissue, dynamic shape motor unit recruitment can alter tissue potentially improve efficiency some locomotion conditions. Despite many challenges, cost estimates derived musculoskeletal simulate function required shown reasonably predict human However, accurate predictions rate still elusive. suggest conceptual may be adapted based on our understanding better variance both within between species.

Language: Английский

Citations

2
Larger and Denser: An Optimal Design for Surface Grids of EMG Electrodes to Identify Greater and More Representative Samples of Motor Units DOI Creative Commons
Arnault H. Caillet, Simon Avrillon, Aritra Kundu

et al.

eNeuro, Journal Year: 2023, Volume and Issue: 10(9), P. ENEURO.0064 - 23.2023

Published: Sept. 1, 2023

The spinal motor neurons are the only neural cells whose individual activity can be noninvasively identified. This is usually done using grids of surface electromyographic (EMG) electrodes and source separation algorithms; an approach called EMG decomposition. In this study, we combined computational experimental analyses to assess how design parameters influence number properties identified units. We first computed percentage units that could theoretically discriminated within a pool 200 simulated when decomposing signals recorded with various sizes interelectrode distances (IEDs). Increasing density, electrodes, size grids, increased our decomposition algorithm discriminate, i.e., up 83.5% (range across conditions: 30.5-83.5%). then from in six participants (range: 2-36 cm

Language: Английский

Citations

27
NeuroMotion: Open-source platform with neuromechanical and deep network modules to generate surface EMG signals during voluntary movement DOI Creative Commons
Shihan Ma, Irene Méndez Guerra, Arnault H. Caillet

et al.

PLoS Computational Biology, Journal Year: 2024, Volume and Issue: 20(7), P. e1012257 - e1012257

Published: July 3, 2024

Neuromechanical studies investigate how the nervous system interacts with musculoskeletal (MSK) to generate volitional movements. Such have been supported by simulation models that provide insights into variables cannot be measured experimentally and allow a large number of conditions tested before experimental analysis. However, current electromyography (EMG), core physiological signal in neuromechanical analyses, remain either limited accuracy or are computationally heavy apply. Here, we computational platform enable future work overcome these limitations presenting NeuroMotion, an open-source simulator can modularly test variety approaches full-spectrum synthesis EMG signals during voluntary We demonstrate NeuroMotion using three sample modules. The first module is upper-limb MSK model OpenSim API estimate muscle fibre lengths activations second BioMime, deep neural network-based generator receives nonstationary parameter inputs, like afore-estimated lengths, efficiently outputs motor unit action potentials (MUAPs). third pool transforms discharge timings units. convolved output BioMime simulate movement. show MUAP waveforms change different levels variations then synthetic two-degree-of-freedom hand wrist movements used augment data for regressing joint angles. Ridge regressors trained on dataset were directly predict angles from data. In this way, was able use-case human forearm electrophysiology hand, wrist, All intermediate available, which allows user study cause-effect relationships complex system, fast iterate algorithms collecting data, validate non-measurable parameters experiments. expect modular will validation generative models, complement empower research.

Language: Английский

Citations

6
NeuroMechanics: Electrophysiological and computational methods to accurately estimate the neural drive to muscles in humans in vivo DOI
Arnault H. Caillet, Andrew Phillips, Luca Modenese

et al.

Journal of Electromyography and Kinesiology, Journal Year: 2024, Volume and Issue: 76, P. 102873 - 102873

Published: March 7, 2024

Language: Английский

Citations

4
Değişken pasif eleman rijitliği içeren bir Hill tipi kas modelinin simülasyonu ve performans analizi DOI Open Access
Faruk Örteş, Bahar Alanbel Ersin

Afyon Kocatepe University Journal of Sciences and Engineering, Journal Year: 2025, Volume and Issue: 25(1), P. 187 - 195

Published: Jan. 28, 2025

Hill tipi kas modelleri başta kas-iskelet sistemleri simülasyonlarında esas alınan kuvvetlerinin hesaplanması olmak üzere kasların çeşitli biyomekanik ve fizyolojik özelliklerinin anlaşılmasında kullanılmaktadırlar. Klasik bir modelde kasılma birimi, paralel elastik elemanlar aracılığıyla yapısındaki aktin, miyozin, titin diğer proteinlerin etkileşimleri matematiksel olarak ifade edilmektedir. Ancak aktif uzama sonrası ortaya çıkan proteini ile ilişkilendirilen kalıntı kuvvet artışlarının bu tip reolojik modellerle simülasyonları yetersiz görünmektedir. Bu çalışmada klasik modeli için pasif eleman katılığındaki değişimin toplam kuvvetinde artışındaki rolü incelenmiştir. Pasif katılık değeri normal değerin yanı sıra kuvvet-uzunluk eğrisinde sağ sol kısımlara kaydırılmış model cevapları elde edilmiştir. Ayrıca farklı eksantrik hızları de simülasyonlar tekrar edilmiş, tüm durumlar kuvvetleri artışları hesaplanmıştır. Sonuçlar göz önüne alındığında, herhangi artışı gözlenmemiştir. aktivasyon uzamaya bağlı katılığının sola kaydırıldığı durumlarda pozitif Buna göre elemanların davranışındaki uygun modifikasyonlar gibi deneysel özelliklerin simüle edilmesinde etkili olabilmektedir.

Citations

0
Matching dynamically varying forces with multi-motor-unit muscle models: a simulation study DOI Creative Commons
Tiina Murtola, Christopher T. Richards

Royal Society Open Science, Journal Year: 2025, Volume and Issue: 12(4)

Published: April 1, 2025

Human muscles exhibit great versatility, not only generating forces for demanding athleticism, but also fine motor tasks. While standard musculoskeletal models may reproduce this they often lack multiple units (MUs) and rate-coded control. To investigate how these features affect a muscle’s ability to generate desired force profiles, we performed simulations with nine alternative MU pool two cases: (i) tibialis anterior muscle an isometric trapezoidal profile, (ii) generic shoulder reaching movement whilst undergoing predetermined length changes. We implemented control strategies, pure feedforward combined feedforward-feedback, each parameterized using elementary The results suggest that the characteristics of pools have relatively little impact on pools’ overall match across all tasks, although performances individual tasks varied. Feedback improved performance nearly physiologically more relevant types were responsive feedback particularly during reaching. well in conditions tested, highlight need consider functional given vast repertoire dynamic by muscles.

Language: Английский

Citations

0
Hill-type models of skeletal muscle and neuromuscular actuators: a systematic review DOI Creative Commons
Arnault H. Caillet, Andrew Phillips, Christopher P. Carty

et al.

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2022, Volume and Issue: unknown

Published: Oct. 18, 2022

Abstract Backed by a century of research and development, Hill-type models skeletal muscle, often including muscle-tendon complex neuromechanical interface, are widely used for countless applications. Lacking recent comprehensive reviews, the field modelling is, however, dense hard-to-explore, with detrimental consequences on innovation. Here we present first systematic review muscle modelling. It aims to clarify literature detailing its contents critically discussing state-of-the-art identifying latest advances, current gaps, potential future directions in For this purpose, fifty-seven criteria-abiding were assessed according completeness evaluation, which identified modelled properties, considered level validation reusability models, as well their strategy calibration. is concluded that most (1) do not significantly advance beyond historical gold standards, (2) neglect importance parameter identification, (3) lack robust validation, (4) reusable other studies. Besides providing convenient tool supported extensive supplementary material navigating literature, results highlight need global recommendations optimize inter-study consistency, knowledge transfer, model reusability.

Language: Английский

Citations

15
The decoding of extensive samples of motor units in human muscles reveals the rate coding of entire motoneuron pools DOI Creative Commons
Simon Avrillon, François Hug, Roger M. Enoka

et al.

eLife, Journal Year: 2024, Volume and Issue: 13

Published: May 9, 2024

Movements are performed by motoneurons transforming synaptic inputs into an activation signal that controls muscle force. The control emerges from interactions between ionotropic and neuromodulatory to motoneurons. Critically, these vary across motoneuron pools differ muscles. To provide the most comprehensive framework date of motor unit activity during isometric contractions, we identified firing extensive samples units in tibialis anterior (129 ± 44 per participant; n=8) vastus lateralis (130 63 muscles contractions up 80% maximal From this unique dataset, rate coding each was characterised as relation its instantaneous applied force, with assumption linear increase force reflects a proportional net excitatory received motoneuron. This natural logarithm function comprised two stages. initial stage marked steep acceleration rate, which greater for low- than medium- high-threshold units. second high- low-threshold Changes were largely non-linear ramp-up ramp-down phases task, but significant prolonged only evident medium-threshold Contrary what is usually assumed, our results demonstrate can follow large variety trends pool. neural perspective, findings indicate how use gain transform limited bandwidths intended

Language: Английский

Citations

2
Consensus for experimental design in electromyography (CEDE) project: Application of EMG to estimate muscle force DOI Creative Commons
Taylor J. M. Dick, Kylie Tucker, François Hug

et al.

Journal of Electromyography and Kinesiology, Journal Year: 2024, Volume and Issue: unknown, P. 102910 - 102910

Published: June 1, 2024

Skeletal muscles power movement. Deriving the forces produced by individual has applications across various fields including biomechanics, robotics, and rehabilitation. Since direct in vivo measurement of muscle force humans is invasive challenging, its estimation through non-invasive methods such as electromyography (EMG) holds considerable appeal. This matrix, developed Consensus for Experimental Design Electromyography (CEDE) project, summarizes recommendations on use EMG to estimate force. The matrix encompasses bipolar surface EMG, high density intra-muscular (1) identify onset during isometric contractions, (2) offset (3) fluctuations (4) dynamic (5) combination with musculoskeletal models contractions. For each application, appropriateness using justification recommendation are provided. achieved consensus makes clear that there limited scenarios which can be used accurately forces. In most cases, it remains important consider activation well state other biomechanical physiological factors- context a formal mechanical model. intended encourage interdisciplinary discussions regarding integration experimental techniques promote advances application towards developing simulations predict healthy clinical populations.

Language: Английский

Citations

2
NeuroMechanics: Electrophysiological and Computational Methods to Accurately Estimate the Neural Drive to Muscles in HumansIn Vivo DOI Creative Commons
Arnault H. Caillet, Andrew Phillips, Luca Modenese

et al.

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: Jan. 4, 2024

Abstract The ultimate neural signal for muscle control is the drive sent from spinal cord to muscles. This comprises ensemble of action potentials discharged by active motoneurons, which transmitted innervated fibres generate forces. Accurately estimating muscles in humans vivo challenging since it requires identification activity a sample motor units (MUs) that representative MU population. Current electrophysiological recordings usually fail this task identifying small samples with over-representation higher-threshold respect lower-threshold MUs. Here, we describe recent advances methods allow more greater numbers MUs than previously possible. obtained large and very dense arrays electromyographic electrodes. Moreover, recently developed computational data augmentation further extend experimental infer full pool. In conclusion, combination new electrode technologies modelling allows an accurate estimate opens perspectives study movement interfacing.

Language: Английский

Citations

1