Video based analysis of dynamic midfoot function and its relationship with Foot Posture Index scores

Area of Science:

• Biomechanics
• Podiatry
• Kinesiology

Background:

• Existing research shows mixed results on the link between static foot posture and injury risk.
• There's a need to connect static foot measures with dynamic function, as dynamic assessments are often impractical in clinical settings.

Purpose of the Study:

• To evaluate the reliability of a novel method for quantifying midfoot movement.
• To determine if the Foot Posture Index (FPI) classification can predict dynamic foot function during walking.

Main Methods:

• Foot type was classified using the Foot Posture Index (FPI) in 280 adults.
• A Video Sequence Analysis (VSA) system quantified midfoot kinematics (navicular drop and minimal navicular height) during walking.
• VSA-derived measures were compared against FPI classifications.

Main Results:

• The VSA system demonstrated high reliability and precision for measuring navicular drop (DeltaNH) and minimal navicular height (NHL).
• DeltaNH showed a significant positive correlation with FPI scores, while NHL decreased as FPI scores increased.
• However, FPI explained only 13.2% of DeltaNH variation and 45% of NHL variation during walking.

Conclusions:

• The Video Sequence Analysis (VSA) system is a reliable and precise tool for quantifying midfoot kinematics.
• Although FPI scores correlate with dynamic foot measures, their predictive power for individual dynamic function is limited.
• Dynamic midfoot assessments are advised for comprehensive clinical evaluations.