Clothing condition does not affect meaningful clinical interpretation in markerless motion capture

Area of Science:

• Biomechanics
• Motion Capture Technology
• Clinical Gait Analysis

Background:

• Markerless motion capture offers ecologically valid movement analysis without physical markers.
• The effect of varied clothing on markerless motion capture accuracy is not well understood.
• Investigating clothing influences is crucial for reliable clinical applications of markerless systems.

Purpose of the Study:

• To assess the impact of two distinct clothing conditions (sport vs. street) on markerless motion capture gait parameters.
• To determine if clothing variations affect clinically meaningful interpretations of gait data.

Main Methods:

• 29 participants performed overground walking at self-selected speeds.
• Markerless motion capture was used to record gait under 'Sport' (gym attire) and 'Street' (casual attire) conditions.
• Segment lengths, spatiotemporal gait parameters, and lower-limb kinematics were compared between conditions.

Main Results:

• Differences in segment lengths were small (0.2–0.9 cm) and below typical marker placement error.
• Statistically significant differences in 7/9 spatiotemporal parameters were observed but were ~10x smaller than minimal detectable changes in pathologies.
• Joint angle variability (2.6°) was comparable to system inter-session variability (2.8°).

Conclusions:

• Clothing type, including sport and casual wear, has a negligible impact on markerless motion capture gait analysis.
• Observed differences are unlikely to alter clinical interpretations of gait pathologies.
• Markerless motion capture remains a viable tool for ecologically valid gait assessments across different clothing conditions.