Background

Obesity and female sex are independent risk factors for knee osteoarthritis and also influence gait mechanics. However, the interaction between obesity and sex on gait mechanics is unclear, which may have implications for tailored gait modification strategies.

Research question

The purpose of this study was to examine the influence of obesity and sex on sagittal and frontal plane knee mechanics during gait in young adults.

Methods

Forty-eight individuals with (BMI = 33.03 ± 0.59; sex:50 % female; age:21.9 ± 2.6 years) and 48 without obesity (BMI:21.59 ± 0.25; sex:50 % female; age:22.9 ± 3.57 years) matched on age and sex completed over-ground gait assessments at a self-selected speed. Two (BMI) by two (sex) analysis of variance was used to compare knee biomechanics during the first half of stance in the sagittal (knee flexion moment [KFM] and excursion [KFE]) and frontal plane (first peak knee adduction moment [KAM], knee varus velocity [KVV]).

Results

We observed a BMI by sex interaction for normalized KFM (P = 0.03). Females had smaller normalized KFM compared to males (P = 0.03), but only in individuals without obesity. Males without obesity had larger normalized KFM compared to males with obesity (P = 0.01), while females did not differ between BMI groups. We observed main effects of sex and BMI group, where females exhibited greater normalized KAM (P < 0.01) and KVV (P < 0.01) compared to males, and individuals with obesity walked with greater KVV compared to those without obesity (P < 0.01). All absolute joint moments were greater in individuals with obesity (all P<0.01) and males had greater absolute KFM compared to females (P < 0.01).

Significance

We observed sex differences in gait mechanics, however, KFM differences between males and females were only evident in individuals without obesity. Further, females and individuals with obesity had a larger KAM and KVV, which may contribute to larger medial compartment joint loading.

中文翻译：

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年轻人行走过程中体重指数和性别对额叶和矢状面膝关节力学的影响

背景

肥胖和女性是膝盖骨关节炎的独立危险因素，也影响步态力学。但是，肥胖与性别之间在步态机制上的相互作用尚不清楚，这可能对定制的步态改变策略有影响。

研究问题

这项研究的目的是检查肥胖和性别对年轻人步态下矢状和额平面膝关节力学的影响。

方法

符合（BMI = 33.03±0.59;性别：50％女性;年龄：21.9±2.6岁）和48个没有肥胖症的人（BMI：21.59±0.25;性别：50％女性;年龄：22.9±3.57岁）在年龄和性别上以自选速度完成地面步态评估。使用两（BMI）乘两（性别）方差分析来比较矢状位（膝盖屈曲力矩[KFM]和偏移[KFE]）和额面（第一峰值膝盖内收力矩[ KAM]，膝内翻速度[KVV]）。

结果

我们通过性别互动观察到BMI归一化KFM（P  = 0.03）。与男性相比，女性的标准化KFM值较小（P  = 0.03），但仅限于没有肥胖的个体。与肥胖男性相比，无肥胖男性的正常KFM值更大（P  = 0.01），而BMI组之间女性没有差异。我们观察到性别和BMI组的主要影响，其中女性比男性表现出更高的标准化KAM（P  <0.01）和KVV（P  <0.01），并且肥胖者的KVV高于无肥胖者（P  <0.01） 。肥胖个体的所有绝对关节力矩都更大（所有P <0.01），男性的绝对KFM高于女性（P  <0.01）。

意义

我们在步态力学上观察到性别差异，但是，男性和女性之间的KFM差异仅在没有肥胖的个体中才明显。此外，肥胖的女性和个体的KAM和KVV较大，这可能会增加内侧隔室的关节负荷。