Hakamata Tomoki, Sakazaki Juntaro, Higuchi Takahiro
Department of Health Promotion Science, Tokyo Metropolitan University, Tokyo, Japan.
Department of Rehabilitation, Kasai Central Hospital, Tokyo, Japan.
Front Sports Act Living. 2024 Aug 14;6:1411037. doi: 10.3389/fspor.2024.1411037. eCollection 2024.
When walking and stepping over an obstacle of a certain height, tripping occurs more frequently with the trailing limb than the leading limb. The present study was designed to address whether collisions involving the trailing limb can be improved with experimental manipulation of the placement of the leading limb after stepping over an obstacle. We used an immersive, virtual obstacle-crossing task to ensure that the collision was not improved simply due to the experience of physical collision with an obstacle.
Fourteen young participants (12 males and 2 females, 28.7 ± 3.5 years) were required to walk and step over a virtual horizontal pole under one of four conditions. In three conditions, participants were required to place their leading foot on a square target located along their walking path after crossing the obstacle. The target was positioned so that it was relatively close to the obstacle (10 cm from the obstacle, referred to hereafter as the closer condition), at a position that would naturally be stepped on in successful trials without a collision (20 cm from the obstacle, the middle condition), or relatively far from the obstacle (40 cm from the obstacle, the farther condition). For the fourth condition, participants were free to select where they would step after stepping over the obstacle (the control condition).
The results showed that the collision rate of the trailing limb was significantly lower under the closer condition than under the other three conditions. Compared to the control condition, under the closer condition the movement of the trailing limb was modified so that obstacle crossing was performed at approximately the moment when the height of the toe of the trailing limb was higher, and the walking speed was slower. These findings suggest that placing the foot of the leading limb closer to the obstacle after crossing the obstacle may ensure safe obstacle avoidance by the trailing limb.
当行走并跨过一定高度的障碍物时，后肢绊倒的频率比前肢更高。本研究旨在探讨在跨过障碍物后，通过对前肢放置位置进行实验性操作，是否可以改善涉及后肢的碰撞情况。我们使用了一种沉浸式虚拟跨障碍任务，以确保碰撞情况的改善并非仅仅因为与障碍物发生实际碰撞的经历。
14名年轻参与者（12名男性和2名女性，年龄28.7±3.5岁）被要求在四种条件之一的情况下行走并跨过一个虚拟的水平杆。在三种条件下，参与者被要求在跨过障碍物后将前脚放在沿其行走路径设置的方形目标上。目标的位置设置为相对靠近障碍物（距离障碍物10厘米，以下简称较近条件）、处于成功试验中自然会踩到且无碰撞的位置（距离障碍物20厘米，中间条件）或相对远离障碍物（距离障碍物40厘米，较远条件）。对于第四种条件，参与者在跨过障碍物后可自由选择落脚点（对照条件）。
结果表明，较近条件下后肢碰撞率显著低于其他三种条件。与对照条件相比，在较近条件下后肢的运动方式有所改变，使得在跨过障碍物时，后肢脚趾高度较高的时刻进行跨障动作，且行走速度较慢。这些发现表明，在跨过障碍物后将前肢的脚放置得更靠近障碍物，可能会确保后肢安全避开障碍物。
