Understanding ageing effects using complexity analysis of foot-ground clearance during walking

Area of Science:

• Biomechanics
• Gerontology
• Signal Processing

Background:

• Gait patterns change with age, impacting balance and locomotion.
• Entropy-based measures effectively analyze physiological signals like gait.
• Minimum toe clearance (MTC) is a sensitive indicator of balance control during walking.

Purpose of the Study:

• To investigate gait complexity in healthy young, healthy elderly, and elderly fall-risk individuals.
• To analyze the regularity and complexity of Minimum Toe Clearance (MTC) time series.
• To understand the impact of aging and balance disorders on MTC complexity.

Main Methods:

• Collected MTC data from 30 healthy young (HY), 27 healthy elderly (HE), and 10 fall-risk (FR) subjects.
• Applied sample entropy (SampEn) analysis to the first 500 MTC data points.
• Calculated SampEn for various window lengths (m) and filtering levels (r) relative to standard deviation (SD).

Main Results:

• FR group showed significantly lower MTC SampEn than HY and HE groups.
• HY group exhibited higher MTC complexity (SampEn) than HE and FR groups.
• SampEn correlated with MTC standard deviation in HY and HE groups, but not in FR, suggesting locomotor disorders alter complexity.

Conclusions:

• Locomotor disorders significantly impact MTC series regularity and complexity.
• Healthy aging does not appear to significantly alter MTC complexity.
• MTC complexity analysis using SampEn shows potential for early diagnosis of gait pathologies.