Trunk Kinematics under Sudden Loading Impact when Adopting Different Foot Postures

摘要

The purpose of this study was to explore the effect of foot posture on trunk biomechanical responseswhen experiencing sudden external loading. Fifteen subjects were recruited to perform a series of suddenloading tasks using three different foot postures with two levels of weight. Our results showed that suddenexternal loading generated the smallest impact when subjects adopted “Staggered Stance”. Compared with“Wide Stance”, “Staggered Stance” significantly decreased the increment of trunk flexion angle, incrementof L5/S1 joint moment, and peak L5/S1 joint anterior-posterior shear force by 21.5%, 6.5%, and 22.5%,respectively. Compared with “Narrow Stance”, the decreases were 15.1%, 3.2%, and 16.2% respectively.Heavier load weight resulted in larger spinal impact. The interaction effect between foot posture andmagnitude of the load was not significant. The findings of this study could be used in reducing the risk oflow back pain when dealing with sudden loading.