Sarantos Lucas, Zeppetelli David J, Dempsey Cole A, Nagai Takashi, Johnson Caleb D
Military Performance Division, U.S. Army Research Institute of Environmental Medicine, 10 General Greene Ave., Natick, MA 01760, USA.
Oak Ridge Institute for Science and Education, 100 Orau Way, Oak Ridge, TN 37830, USA.
Sensors (Basel). 2025 Apr 23;25(9):2656. doi: 10.3390/s25092656.
Shock attenuation may be a clinically feasible method to assess changes in lower extremity joint loading induced by gait modifications, such as decreasing foot strike angle (forefoot striking). The purpose of this study was to identify changes in lower extremity shock attenuation between habitual and forefoot strike gait conditions. Eighteen participants ran on a treadmill with their habitual gait and an instructed forefoot strike gait. Shock attenuation was measured with inertial measurement units as the ratio of proximal to distal peak resultant/vertical accelerations, with three sensor combinations: ankle to below/above knee (BK/A; AK/A) and AK/BK. Three participants were excluded who were habitual forefoot strikers or failed to decrease their foot strike angle by at least 5° in the forefoot strike condition. The results showed significantly greater resultant shock attenuation in the forefoot strike compared to the habitual condition for BK/A (mean Δ = 0.13, = 0.004) and AK/A (mean Δ = 0.23, = 0.007). No significant differences were found for AK/BK or vertical shock attenuation. These results suggest that shock attenuation may not reflect joint-specific loading changes that have been shown for forefoot striking (i.e., increased ankle/shank and decreased knee moments). However, it may capture changes in overall lower extremity loading (i.e., decreased vertical ground reaction forces).
冲击衰减可能是一种临床上可行的方法，用于评估由步态改变（如减小足跟着地角度，即前脚掌着地）引起的下肢关节负荷变化。本研究的目的是确定习惯性步态和前脚掌着地步态条件下下肢冲击衰减的变化。18名参与者在跑步机上以其习惯性步态和指令性前脚掌着地步态跑步。使用惯性测量单元测量冲击衰减，作为近端与远端峰值合力/垂直加速度的比值，有三种传感器组合：脚踝至膝盖以下/以上（BK/A；AK/A）和AK/BK。三名习惯性前脚掌着地者或在前脚掌着地条件下未能将足跟着地角度至少减小5°的参与者被排除。结果显示，与习惯性步态相比，前脚掌着地时BK/A（平均差值=0.13，P=0.004）和AK/A（平均差值=0.23，P=0.007）的合力冲击衰减显著更大。AK/BK或垂直冲击衰减未发现显著差异。这些结果表明，冲击衰减可能无法反映前脚掌着地所显示的特定关节负荷变化（即脚踝/小腿力矩增加和膝盖力矩减小）。然而，它可能捕捉到下肢整体负荷的变化（即垂直地面反作用力减小）。
