Identifying differences in gait adaptability across various speeds using movement synergy analysis.

Area of Science:

• Biomechanics
• Human Movement Science
• Neurology

Background:

• Gait adaptability is crucial for maintaining balance during walking.
• Movement synergies, coordinated patterns of muscle activation, underpin complex motor tasks like walking.
• Understanding how movement synergies relate to gait variability is key for assessing and improving mobility.

Purpose of the Study:

• To identify movement synergies that differentiate healthy adults based on gait adaptability across various walking speeds.
• To investigate the association between movement synergies and lower-limb coordination variability (Deviation Phase, DP).
• To examine the moderating effect of movement synergies on the relationship between DP and arm-swing smoothness (NJI).

Main Methods:

• Principal component analysis of whole-body marker data during treadmill walking at different speeds.
• Calculation of Deviation Phase (DP) and arm-swing smoothness (NJI) from perturbed walking trials.
• Linear mixed-effects models to assess the relationship between movement synergy metrics (PAkRMS) and gait variability parameters.

Main Results:

• The push-off mechanism synergy (PA4RMS) significantly impacted DP, with speed-dependent effects.
• A synergy related to right-left weight transfer (PA6RMS) was identified as a key factor in explaining variations in the combined DP and NJI.
• Individuals with greater control over specific kinematic synergies showed variations in perturbed walking.

Conclusions:

• Movement synergies play a significant role in gait adaptability and proactive balance correction during the double-support phase.
• The findings support the potential application of movement synergy analysis in targeted rehabilitation programs.
• Further research is needed to explore the influence of walking speed and leg dominance on movement synergies and their generalizability to patient populations.