Identifying the Key Biomechanical Features of Movement Adaptation during Exoskeleton-Assisted Locomotion

2026-08-07

AI Summary

This study addresses the limited understanding of individual adaptation dynamics during exoskeleton-assisted walking and their temporal evolution. Integrating motion capture, metabolic measurements, and multivariate time-series analysis, the research characterizes dynamic changes in lower-limb kinematics, inter-joint coordination, and metabolic cost at both group and individual levels. The findings reveal that kinematic adaptation exhibits pronounced fluctuations during the swing phase, with asynchronous convergence across joints, while metabolic responses display substantial inter-individual heterogeneity and frequently fail to reach steady state. These results underscore the highly individualized nature of the adaptation process, challenging conventional assumptions of steady-state behavior and highlighting the necessity of modeling individual time-series trajectories to enable precise, personalized exoskeleton assistance.

Abstract

The understanding of natural human adaptation during exoskeleton-assisted locomotion - particularly individual differences in adaptation behaviors and temporal progression - remains limited. In this work, we investigate temporal evolution of biomechanical variables to uncover participant-specific adaptation strategies across different exoskeleton-assisted locomotion scenarios. Nine healthy participants performed treadmill walking under three conditions: without an exoskeleton, with exoskeleton active ankle assistance, and with exoskeleton zero-torque. Lower limb kinematics, inter-joint coordination, and metabolic cost of transport (MCoT) were analyzed at both the group and individual levels. Results indicate that adaptation is gradual and highly individualized, with substantial variability in convergence timing and movement patterns across participants. Kinematic adaptation occurred asynchronously across lower limb, with larger fluctuations during the swing phase. Metabolic responses were heterogeneous and often non-convergent, highlighting the limitations of steady-state assumptions commonly adopted in the literature. These findings emphasize the importance of individual-level, temporal evolution analyses for understanding adaptation dynamics in exoskeleton use.

Problem

• exoskeleton-assisted locomotion
• movement adaptation
• individual differences
• temporal evolution
• biomechanical features

Innovation

• individualized adaptation
• temporal evolution
• biomechanical variables
• metabolic cost of transport
• exoskeleton-assisted locomotion