Background

Patients with hip osteoarthritis (OA) exhibit an increased step width (SW) during walking before and up to 2 years after total hip arthroplasty. Wider SW is associated with a reduction in the external knee adduction moment (KAM), but there is a lack of research regarding the effect of SW on the hip adduction moment (HAM).

Research question

Is a wider SW an effective compensatory mechanism to reduce the hip joint loading? We hypothesized that (1) an increased SW reduces, (2) a decreased SW increases the KAM/HAM, and (3) secondary kinematic gait changes have an effect on the KAM/HAM.

Methods

Twenty healthy individuals (24.0 ± 2.5 years of age) underwent instrumented gait analyses with 4 different subject-specific SW modifications (habitual, halved, double, and triple SW). The resulting external KAMs and HAMs were compared using statistical parametric mapping (SPM).

Results

Post hoc testing demonstrated significantly lower HAM for both the double (p < 0.001, 15–31 % and 61–98 % of the stance phase) and the triple SW (p < 0.001, 1–36 % and 58–98 %) compared to the habitual SW. The extent of the reduction at the first and second peak was comparable for HAM (15–25 % reduction) and less pronounced at the first peak of KAM (9–11 % reduction) compared to the second peak of KAM (19–28 % reduction). In contrast, halving the SW did not lead to a significant change in KAM or HAM compared to the habitual SW (p > 0.009).

Significance

An increase in SW is an effective and simple gait mechanism to reduce the frontal plane knee and hip joint moments. However, hypothesis 2 could not be confirmed, as halving the SW did not cause a significant change in KAM or HAM. Given the results of the present study, gait retraining with regard to an increased SW may be an adequate, noninvasive option for the treatment of patients with hip OA.

中文翻译：

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受试者特定步宽修改对步态过程中膝关节和髋关节内收力矩的影响

背景

髋关节骨性关节炎 (OA) 患者在全髋关节置换术前和术后 2 年内行走时步幅 (SW) 增加。更宽的 SW 与减少外膝内收力矩 (KAM) 相关，但缺乏关于 SW 对髋内收力矩 (HAM) 影响的研究。

研究问题

更宽的 SW 是减少髋关节负荷的有效补偿机制吗？我们假设 (1) 增加的 SW 减少，(2) 减少的 SW 增加 KAM/HAM，和 (3) 二次运动学步态变化对 KAM/HAM 有影响。

方法

20 名健康个体（24.0 ± 2.5 岁）接受了仪器化步态分析，其中有 4 种不同的受试者特定的 SW 修改（习惯性、减半、双重和三重 SW）。使用统计参数映射 (SPM) 比较生成的外部 KAM 和 HAM。

结果

事后测试表明，与三重 SW（ p < 0.001、15-31% 和 61-98% 的站立期）和三重 SW（p < 0.001、1-36% 和 58-98%）相比， HAM 显着降低到习惯性的SW。与 KAM 的第二个峰（19-28%）相比，HAM 的第一个峰和第二个峰的减少程度（减少 15-25%）相当，KAM 的第一个峰（减少 9-11%）不太明显减少）。相比之下，与习惯性 SW 相比，将 SW 减半并不会导致 KAM 或 HAM 发生显着变化（p > 0.009）。

意义

SW 的增加是一种有效且简单的步态机制，可减少额平面膝关节和髋关节力矩。然而，假设 2 无法得到证实，因为将 SW 减半不会导致 KAM 或 HAM 发生显着变化。鉴于本研究的结果，关于增加 SW 的步态再训练可能是治疗髋关节 OA 患者的一种适当的、非侵入性的选择。