Sex Difference in Running Stability Analyzed Based on a Whole-Body Movement: A Pilot Study

Area of Science:

• Biomechanics
• Sports Science
• Human Movement Analysis

Background:

• Running injuries present a significant risk, with potential sex-specific contributing factors.
• Understanding sex differences in running mechanics is crucial for effective injury prevention and rehabilitation.

Purpose of the Study:

• To investigate sex differences in whole-body running stability during self-preferred speed treadmill running.
• To identify specific movement patterns associated with sex-based variations in running stability.

Main Methods:

• Principal Component Analysis (PCA) was used to decompose whole-body kinematic data into principal movements (PMs).
• Running stability was quantified using the largest Lyapunov exponent (LyE) for variability, relative standard deviation (rSTD) for movement structure, and root mean square (RMS) for neuromuscular control.
• Sex effects were analyzed on PCA-derived variables for individual PMs in 22 recreational runners.

Main Results:

• Significant sex differences were observed in specific principal movements.
• Female runners demonstrated lower stability (higher LyE) in mid-stance phase movements (PM4-5).
• Females exhibited greater contribution and control (higher rSTD and RMS) in swing-phase movements (PM1) compared to males.

Conclusions:

• Inherent sex differences exist in running stability and movement control strategies.
• These findings highlight distinct neuromuscular adaptations between sexes during running.
• Knowledge of sex-specific running stability can enhance sports injury prevention and rehabilitation programs.