Inai Takuma, Takabayashi Tomoya, Edama Mutsuaki, Kubo Masayoshi
Institute for Human Movement and Medical Sciences, Niigata University of Health and Welfare, Niigata City, Japan.
PeerJ. 2019 Nov 19;7:e8110. doi: 10.7717/peerj.8110. eCollection 2019.
Increased daily cumulative hip moment in the frontal plane (i.e., the product of hip moment impulse in the frontal plane during the stance phase and mean steps per day) is a risk factor for progression of hip osteoarthritis. Although hip osteoarthritis generally causes a decrease in the walking speed, its effect on hip moment impulse in the frontal plane is unclear. The purpose of this study was to examine the relationship between decrease in walking speed and hip moment impulse in the frontal plane.
We used a public dataset of treadmill walking in 17 older adults (mean (SD) age: 63.2 (8.0) years). The subjects walked on the treadmill for 30 s under five conditions: (1) 40% of comfortable non-dimensional speed (CNDS), (2) 55% CNDS, (3) 70% CNDS, (4) 85% CNDS, and (5) 100% CNDS. The hip moment impulse in the frontal plane non-normalized (or normalized) to step length (Nm s/kg [or Nm s/(kg m)]) for each condition was calculated. Furthermore, the relationship between walking speed and hip moment impulse in the frontal plane non-normalized (or normalized) to step length was examined using regression analysis based on a previous study.
A decrease in non-dimensional speed (i.e., walking speed) significantly increased the non-normalized (or normalized) hip moment impulse in the frontal plane during the stance phase. The relationship between walking speed and non-normalized (or normalized) hip moment impulse in the frontal plane was fitted by a second-order polynomial.
This study revealed that a decrease in walking speed increased the non-normalized (or normalized) hip moment impulse in the frontal plane in healthy older adults. This finding is useful for understanding the relationship between walking speed and hip moment impulse in the frontal plane and suggests that a decrease in walking speed may actually increase the daily cumulative hip moment in the frontal plane of patients with hip osteoarthritis.
额状面每日累积髋部力矩增加（即站立期额状面髋部力矩冲量与每日平均步数的乘积）是髋骨关节炎进展的一个危险因素。虽然髋骨关节炎通常会导致步行速度下降，但其对额状面髋部力矩冲量的影响尚不清楚。本研究的目的是探讨步行速度下降与额状面髋部力矩冲量之间的关系。
我们使用了一个包含17名老年人（平均（标准差）年龄：63.2（8.0）岁）在跑步机上行走的公共数据集。受试者在五种条件下在跑步机上行走30秒：（1）舒适无量纲速度（CNDS）的40%，（2）55%CNDS，（3）70%CNDS，（4）85%CNDS，以及（5）100%CNDS。计算每种条件下未归一化（或归一化）至步长的额状面髋部力矩冲量（Nm·s/kg[或Nm·s/(kg·m)]）。此外，基于先前的一项研究，使用回归分析研究了未归一化（或归一化）至步长的步行速度与额状面髋部力矩冲量之间的关系。
无量纲速度（即步行速度）下降显著增加了站立期额状面未归一化（或归一化）的髋部力矩冲量。步行速度与额状面未归一化（或归一化）的髋部力矩冲量之间的关系由二阶多项式拟合。
本研究表明，步行速度下降会增加健康老年人额状面未归一化（或归一化）的髋部力矩冲量。这一发现有助于理解步行速度与额状面髋部力矩冲量之间的关系，并表明步行速度下降实际上可能会增加髋骨关节炎患者额状面的每日累积髋部力矩。
