Abstract

Recovery stepping in response to forward slips has the potential to not only rebuild the base of support to prevent backward falling, but also provide extra limb support to prevent downward falling. Hence, recovery stepping is often necessary for fall prevention following an unexpected slip. However, less is known about whether recovery foot placement could affect the likelihood of recovery following a slip. The purpose of this study was to determine whether there is an optimal recovery landing zone within which older adults have a higher likelihood of recovery. 195 participants experienced a novel, unannounced forward slip while walking on a 7-m walkway. The center of mass (COM) stability (computed from its position and velocity), vertical limb support (computed from change in hip kinematics), and recovery limb joint moments (computed from joint kinematics and ground reaction force) in the sagittal plane were analyzed. The results showed that a longer distance between recovery foot landing position and the projected COM position at recovery foot touchdown (relative recovery step placement) was conducive to stability improvement but adverse to limb support enhancement, and vice versa for a shorter distance. Relative recovery step placement could predict the recovery likelihood with an accuracy of 67.3%, and the recovery rate was greater than 50% when the distance between recovery foot and COM is less than 0.3 × foot length. This study also found more posterior stepping could be attributed to insufficient ankle plantar flexor and hip flexor moments in the pre-swing phase, while more anterior stepping was induced by insufficient hip and knee extensor moments in the following swing phase.

中文翻译：

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在步行过程中是否有针对滑倒引起的向后下落的最佳恢复台阶着陆区？

摘要

响应于前滑而进行的恢复踏步不仅可能重建支撑基础以防止向后倒下，而且还可能提供额外的肢体支撑以防止向下倒下。因此，为了防止意外滑倒后的跌倒，通常需要恢复台阶。然而，人们对于康复脚的放置是否会影响滑倒后康复的可能性知之甚少。这项研究的目的是确定是否有一个最佳的恢复着陆区，在该区域内老年人具有较高的恢复可能性。195名参与者在7米的人行道上行走时，经历了一种新颖的突击滑音。质心（COM）稳定性（根据其位置和速度计算），垂直肢体支撑（根据髋部运动学变化计算），并分析矢状面的恢复肢关节力矩（由关节运动学和地面反作用力计算）。结果表明，恢复脚着地位置与恢复脚着地时的预计COM位置（相对恢复步骤放置）之间的距离较长，有利于稳定性的改善，但不利于肢体支撑的增强，反之亦然。相对恢复步骤的放置可以预测恢复可能性，准确性为67.3％，并且当恢复脚和COM之间的距离小于0.3×脚长时，恢复率大于50％。这项研究还发现，更多的后移可能是由于在前摆动阶段踝足plant屈和髋屈肌力矩不足，