Department of Mechanical Engineering, Texas A&M University, College Station, Texas, United States of America.
Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America.
PLoS One. 2020 Mar 12;15(3):e0230019. doi: 10.1371/journal.pone.0230019. eCollection 2020.
Falls cause negative impacts on society and the economy. Slipping is a common initiating event for falling. Yet, individuals differ in their ability to recover from slips. Persons experiencing mild slips can accommodate the perturbation without falling, whereas severe slipping is associated with inadequate or slow pre- or post-slip control that make these individuals more prone to fall. Knowing the discrepancies between mild and severe slippers in kinematic and kinetic variables improves understanding of adverse control responsible for severe slipping. This study examined differences across these participants with respect to center of mass (COM) height, sagittal angular momentum (H), upper body kinematics, and the duration of single/double phase. Possible causality of such relationships was also studied by observing the time-lead of the deviations. Twenty healthy young adults performed walking trials in dry and slippery conditions. They were classified into mild and severe slippers based on their heel slipping speed. No inter-group differences were observed in the upper extremity kinematics. It was found that mild and severe slippers do not differ in the studied variables during normal gait; however, they do show significant differences through slipping. Compared to mild slippers, sever slippers lowered their COM height following a slip, presented higher H, and shortened their single support phase (p-value<0.05 for all). Based on the time-lead observed in H over all other variables suggests that failure to control angular momentum may influence slip severity.
跌倒对社会和经济造成负面影响。滑倒是跌倒的常见起始事件。然而，个体在从滑倒中恢复的能力上存在差异。轻度滑倒的人可以在不跌倒的情况下适应扰动，而严重滑倒则与预滑或后滑控制不足或缓慢有关，这使得这些人更容易跌倒。了解轻度和重度滑倒者在运动学和动力学变量方面的差异，可以更好地理解导致严重滑倒的不良控制。本研究通过观察偏差的时间领先，研究了这些参与者在质心高度、矢状角动量（H）、上半身运动学和单/双相持续时间方面的差异。还通过观察偏差的时间领先，研究了这些关系的可能因果关系。20 名健康的年轻成年人在干燥和湿滑的条件下进行了行走试验。他们根据脚跟滑动速度被分为轻度和重度滑倒者。在上肢运动学方面，两组之间没有观察到组间差异。结果发现，在正常步态中，轻度和重度滑倒者在研究变量上没有差异；然而，在滑倒过程中，它们确实表现出显著差异。与轻度滑倒者相比，严重滑倒者在滑倒后降低了质心高度，H 值更高，单支撑阶段更短（所有 p 值均<0.05）。根据 H 在所有其他变量上的时间领先，表明控制角动量失败可能会影响滑倒的严重程度。
