Effect of stiffness difference of forefoot transverse arch on foot biomechanics

The transverse arch of the forefoot (FTA) is the only coronal arch among the foot's three arches and contributes over 40% of the foot's longitudinal stiffness. The present study investigated the effect of different FTA stiffness on foot biomechanics and motor performance. FTA stiffness was categorized into control and high-stiffness groups based on FTA length under maximum anterior tilt, measured via imaging. Kinetic data such as plantar pressure, impulse, and loading rate were collected from 16 healthy subjects performing drop jumps. Finite element analysis simulated metatarsal displacement and stress distribution during landing. Results showed significant differences in maximum plantar pressure at Ml, M2, and M3 between groups, with higher pressures in the high-stiffness group. The high-stiffness group exhibited greater loading rates and force-time integrals at M1. FTA collapse and width increase were slightly different between groups, with the largest stress observed in the M2 area during landing. The findings indicate that FT A stiffness affects foot stability and cushioning, primarily influencing the width rather than the height of the FTA.