Excursion variability of joint angle during walking in outdoor environment

The purpose of this study is to examine the difference in the kinematic profiles during walking between indoor and outdoor environments. Ten healthy young males were participated in this study. The subjects walked about 90m in each environment at a self-selected preferred walking speed. The joint kinematic of the lower extremity during walking in both environments were measured using seven inertial measurement units. The coefficients of variation (CV) of the joint angular excursion across 30 gait cycles were compared by Wilcoxon signed ranks tests. The CV of the ankle plantar flexion excursion in the early stance increased in outdoor environment compared to that of indoor. This is speculated due to the ankle plantar flexion motion in the early stance phase that functions as the shock absorber against the irregularities of the environment.