Intra-foot biomechanics during running

Abstract

Intra-foot kinematics during walking have often been documented using multi-segment foot models. However, the intra-foot kinematics during running remain unclear. Firstly, we investigated changes in kinematic coupling among rearfoot, midfoot, and forefoot during running and walking in normal foot. Strong coupling was observed both tasks between rearfoot eversion/ inversion and midfoot eversion/ inversion, between midfoot eversion/ inversion and forefoot eversion/ inversion. Secondly, we investigated to quantify coordination among rearfoot, midfoot, and forefoot during running in normal foot. Coordination was calculated by using the modified vector coding technique. During the absorption phase, rearfoot–midfoot coordination in the frontal planes was mostly in-phase (rearfoot and midfoot eversion with similar amplitudes). Lastly, we investigated sex differences associated with rearfoot, midfoot, and forefoot kinematics during running. In the rearfoot angle and midfoot angle, females showed a significantly greater range of motion in the sagittal plane as compared with males. Furthermore, anti-phase with proximal dominancy in proportion of frontal rearfoot-shank vs. midfoot-rearfoot couple and midfoot-rearfoot vs. forefoot-midfoot couple in females was significantly increased compared to that in males. In the future, we will verify the intra-foot biomechanics running for patients with flatfoot and pes cavus.