Sensory modulation of gait characteristics in human locomotion: A neuromusculoskeletal modeling study

Andrea Di Russo; Dimitar Stanev; Stéphane Armand; Auke Ijspeert

doi:10.1371/journal.pcbi.1008594

Sensory modulation of gait characteristics in human locomotion: A neuromusculoskeletal modeling study

PLoS Comput Biol. 2021 May 19;17(5):e1008594. doi: 10.1371/journal.pcbi.1008594. eCollection 2021 May.

Authors

Andrea Di Russo¹, Dimitar Stanev¹, Stéphane Armand², Auke Ijspeert¹

Affiliations

¹ Biorobotics Laboratory, École polytechnique fédérale de Lausanne, School of Engineering, Institute of Bioengineering, Lausanne, Switzerland.
² Kinesiology Laboratory, Geneva University Hospitals and University of Geneva, Geneva, Switzerland.

Abstract

The central nervous system of humans and other animals modulates spinal cord activity to achieve several locomotion behaviors. Previous neuromechanical models investigated the modulation of human gait changing selected parameters belonging to CPGs (Central Pattern Generators) feedforward oscillatory structures or to feedback reflex circuits. CPG-based models could replicate slow and fast walking by changing only the oscillation's properties. On the other hand, reflex-based models could achieve different behaviors through optimizations of large dimensional parameter spaces. However, they could not effectively identify individual key reflex parameters responsible for gait characteristics' modulation. This study investigates which reflex parameters modulate the gait characteristics through neuromechanical simulations. A recently developed reflex-based model is used to perform optimizations with different target behaviors on speed, step length, and step duration to analyze the correlation between reflex parameters and their influence on these gait characteristics. We identified nine key parameters that may affect the target speed ranging from slow to fast walking (0.48 and 1.71 m/s) as well as a large range of step lengths (0.43 and 0.88 m) and step duration (0.51, 0.98 s). The findings show that specific reflexes during stance significantly affect step length regulation, mainly given by positive force feedback of the ankle plantarflexors' group. On the other hand, stretch reflexes active during swing of iliopsoas and gluteus maximus regulate all the gait characteristics under analysis. Additionally, the results show that the hamstrings' group's stretch reflex during the landing phase is responsible for modulating the step length and step duration. Additional validation studies in simulations demonstrated that the modulation of identified reflexes is sufficient to regulate the investigated gait characteristics. Thus, this study provides an overview of possible reflexes involved in modulating speed, step length, and step duration of human gaits.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Biomechanical Phenomena
Computational Biology
Computer Simulation
Gait / physiology*
Humans
Locomotion / physiology*
Models, Anatomic
Models, Neurological*
Muscle, Skeletal / innervation
Muscle, Skeletal / physiology
Musculoskeletal Physiological Phenomena
Musculoskeletal System / anatomy & histology
Musculoskeletal System / innervation
Psychomotor Performance / physiology
Reflex, Stretch / physiology
Walking / physiology

Grants and funding

This work is part of SimGait Sinergia project funded by the Swiss National Science Foundation (http://p3.snf.ch/project-177179): grant agreement No. 177179 (SA, AI). There was no additional external funding received for this study. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.