Foot Progression Angle Modulates Knee Loading During Walking in Individuals with Flexible Flatfoot.

Area of Science:

• Biomechanics
• Orthopedics
• Sports Medicine

Background:

• Flexible flatfoot (FFF) is associated with altered lower limb biomechanics.
• Understanding tibiofemoral loading and meniscal stress in FFF is crucial for injury prevention and management.

Purpose of the Study:

• To evaluate tibiofemoral loading and medial meniscal stress distribution in FFF during walking.
• To investigate the effects of different foot progression angles (FPAs) on these parameters.

Main Methods:

• Gait analysis of 28 FFF patients under neutral, toe-in, and toe-out FPAs.
• Kinematic and kinetic data used to estimate tibiofemoral forces via OpenSim.
• Finite element (FE) modeling of the knee to assess meniscal stress and contact pressure.

Main Results:

• Tibiofemoral force increased in the toe-in condition, particularly in males.
• Peak stresses and contact pressure on the medial meniscus were mainly in the anterior region.
• Toe-in FPA resulted in the lowest peak stresses, while toe-out FPA showed the highest.

Conclusions:

• Foot progression angle significantly modulates knee joint loading in FFF patients.
• A neutral FPA offers stable knee loading.
• Individualized gait interventions are necessary for FFF management, considering foot morphology, sex, and functional goals.