Foot Flexibility and Alignment Are Weakly Correlated with Multisegment Foot Kinematics During the Landing Task.

Area of Science:

• Biomechanics
• Sports Medicine
• Orthopedics

Background:

• Flat feet are associated with increased foot motion during dynamic activities, a known risk factor for sports injuries.
• Limited research exists on how foot flexibility influences foot kinematics during landing.
• This study investigates the link between foot alignment, flexibility, and multisegment foot motion in healthy individuals during landing.

Purpose of the Study:

• To examine the relationship between foot alignment and flexibility with multisegment foot kinematics.
• To understand how foot structure influences dynamic foot motion during a double-leg landing task.
• To differentiate the effects of foot alignment versus flexibility on landing biomechanics.

Main Methods:

• Thirty-eight healthy volunteers underwent assessment of foot alignment (normalized navicular height truncated - NNHt) and flexibility (navicular drop - ND test).
• A multisegment foot model captured shank, rearfoot, midfoot, and forefoot motion during a 30 cm drop landing.
• Peak angles and range of motion for each segment were analyzed from initial contact to 200 ms post-landing.

Main Results:

• Normalized navicular height truncated (NNHt) showed a significant inverse correlation with peak rearfoot eversion angle.
• Navicular drop (ND) test values correlated significantly with midfoot dorsiflexion and forefoot inversion excursion.
• No significant correlations were found between NNHt/ND and other measured kinematic outcomes.

Conclusions:

• Foot alignment and flexibility are distinct measures that correlate with different aspects of foot motion during landing.
• Evaluating foot alignment and flexibility separately is crucial for a comprehensive understanding of foot function.
• Predicting complex foot motion during landing solely based on static alignment and flexibility measures may be insufficient.