Reliability and validity of the Microsoft Kinect for evaluating static foot posture.

Area of Science:

• Biomechanics
• Medical Imaging
• Clinical Assessment

Background:

• Accurate foot posture evaluation is crucial for injury screening in clinical settings.
• Disagreement exists regarding the most clinically useful assessment methods.
• The Microsoft Kinect offers a potentially accurate, objective, and accessible imaging solution for static foot posture analysis.

Purpose of the Study:

• To assess the intra-rater reliability and validity of the Microsoft Kinect system for evaluating static foot posture.
• To compare Kinect-based assessments with traditional visual Foot Posture Index (FPI) and a 3D motion analysis (3DMA) system.

Main Methods:

• Static foot posture was assessed using visual FPI, a 3DMA system, and the Microsoft Kinect.
• Spearman's rho correlation was used to evaluate intra-rater reliability and concurrent validity.
• Linear regression analyzed the Kinect's ability to predict the total visual FPI score.

Main Results:

• The Kinect demonstrated moderate to good intra-rater reliability (ρ = 0.62–0.78) and correlations with 3DMA (ρ = 0.51–0.85) for several foot posture items.
• Visual FPI showed poor to moderate intra-rater reliability (ρ = 0.17–0.63) and poor correlations with Kinect and 3DMA.
• Kinect-derived FPI items predicted 61% of the variance in the total visual FPI score.

Conclusions:

• Kinect-based foot posture measurements were more reliable than visual FPI assessments.
• The Kinect system demonstrated validity when compared to a 3DMA system.
• The Kinect shows significant potential for accurate static foot posture evaluation in clinical practice.