Graduate School of Comprehensive Rehabilitation, Osaka Prefecture University, Habikino City, Osaka, Japan; Pacific Supply Co. Ltd., Daito City, Osaka, Japan.
Department of Biomedical Engineering, Faculty of Engineering, The Hong Kong Polytechnic University, Hong Kong, China.
Gait Posture. 2021 Oct;90:252-260. doi: 10.1016/j.gaitpost.2021.08.011. Epub 2021 Aug 16.
The socket reaction moment (SRM) has been reported to change because of alignment changes in transtibial prosthetic sockets. However, the influence of prosthetic foot alignment on SRM remains unclear.
Are SRMs predictable from alignment changes of prosthetic feet?
Ten users of transtibial prostheses participated in this study. Under five alignment conditions (3 ° plantarflexion and dorsiflexion, 6 ° inversion and eversion, and baseline alignment), temporal-spatial parameters and sagittal and coronal SRMs were measured during walking. Cadence, walking speed, step time, single support time, and step length were compared. The maximum/minimum SRM, % stance (timing) of the maximum/minimum SRM, Zero-cross, and SRMs at 5 %, 20 %, and 75 % stance were extracted and compared. Repeated measures analysis of variance or Friedman tests, and linear regression analyses were conducted for statistical analyses (i.e., alignment conditions as independent variables and SRM parameters as dependent variables).
The SRMs at 5%, 20 %, and 75 % stance showed significant differences under coronal angular changes. The minimum SRM, % stance of the minimum/maximum SRM, and Zero-cross showed significant differences under sagittal alignment changes. In linear regression analysis, the minimum SRM, % stance of the minimum/maximum SRM, SRM at 20 % stance, and Zero-cross were significant dependent variables in the sagittal plane. The maximum/minimum SRM, SRM at 20 % and 75 % stance, and % stance of the minimum SRM were significant dependent variables in the coronal plane.
The results indicated that the changes in prosthetic feet angles may predict the magnitude of SRM (maximum/minimum SRM, SRM at 20 % and 75 % stance) in the coronal plane, and the timing of SRM (Zero-cross, % stance of the maximum/minimum SRM) in the sagittal plane. These findings suggest that the SRM may be useful for evaluating foot alignment in transtibial prostheses.
Socket 反应力矩（SRM）已被报道会因胫骨假肢接受腔的对线变化而改变。然而，假肢足对线变化对 SRM 的影响尚不清楚。
SRM 是否可以根据假肢足的对线变化来预测？
本研究纳入 10 名胫骨截肢患者。在 5 种对线条件下（3°跖屈和背屈、6°内翻和外翻、基线对线），测量患者行走时的时空参数和矢状面及冠状面 SRM。比较了步频、步行速度、步时、单支撑时间和步长。提取并比较了最大/最小 SRM、最大/最小 SRM 的%站立（时间）、零交叉和站立 5%、20%和 75%时的 SRM。采用重复测量方差分析或 Friedman 检验以及线性回归分析进行统计分析（即，对线条件为自变量，SRM 参数为因变量）。
冠状面角度变化时，5%、20%和 75%站立位时的 SRM 存在显著差异。矢状面对线变化时，最小 SRM、最小/最大 SRM 的%站立、零交叉存在显著差异。线性回归分析中，矢状面中最小 SRM、最小/最大 SRM 的%站立、20%站立位时的 SRM 和零交叉是显著的因变量；冠状面中最大/最小 SRM、20%和 75%站立位时的 SRM 以及最小 SRM 的%站立是显著的因变量。
结果表明，假肢足角度的变化可能预测冠状面中 SRM（最大/最小 SRM、20%和 75%站立位时的 SRM）的大小和矢状面中 SRM（零交叉、最大/最小 SRM 的%站立）的时间。这些发现提示 SRM 可能有助于评估胫骨假肢的足对线。
