Background

Women are twice as likely as men to develop knee osteoarthritis (OA), and with it experience greater losses of physical function and disability. A change in the mechanical environment of the joint is a key initiating factor for knee OA. Differences in morphology, joint injury risk, and hormonal shifts in mid-life are often considered factors which increase OA risk for women. Pregnancy, a time of significant hormonal, morphological, and biomechanical change, has received comparably less attention. If morphological and biomechanical changes persist postpartum, this could increase OA risk for parous (childbearing) women.

Research question

Are lower limb gait mechanics different between healthy nulliparous (non-childbearing) and parous (childbearing) women?

Methods

Twenty-eight self-reported not pregnant female participants (14 parous, 14 nulliparous) were recruited for the study. Nulliparous participants had never given birth to a child. Parous participants had given birth to at least one full-term infant (37–42 weeks) without complications between one to five years before data collection. Motion capture of participants’ preferred, fast, and set (1.4 m/s) walking speeds was conducted. Repeated measures ANOVA were performed to test for significant group differences in joint kinematics and kinetics.

Results

There was a significant main effect of group indicating a larger knee flexion angle at toe off (p = 0.0002), smaller knee extension moment at heel strike (p = 0.0006), smaller first peak knee flexion moment (p = 0.040), and smaller peak hip adduction moment for the parous group compared to the nulliparous group (p = 0.003). Static Q-angle did not differ between groups.

Significance

Alteration in mechanics from the habitual loading pattern are thought to increase risk of OA. Smaller knee moments in post-partum women could alter the mechanical stimulus to cartilage, and should be investigated in conjunction with cartilage health measures to determine the link with OA initiation.

中文翻译：

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平价对膝OA开始的生物力学危险因素的影响

背景

女性患膝骨关节炎（OA）的可能性是男性的两倍，并因此而遭受更大的身体机能和残疾损失。关节机械环境的变化是导致膝骨关节炎的关键因素。形态，关节损伤风险和中年荷尔蒙变化的差异通常被认为是增加女性OA风险的因素。怀孕是激素，形态和生物力学发生重大变化的时期，受到的关注相对较少。如果产后形态和生物力学变化持续存在，可能会增加产后妇女的OA风险。

研究问题

健康的未生育（未生育）妇女和未生育（未生育）妇女的下肢步态机制是否不同？

方法

本研究招募了28名自我报告未怀孕的女性参与者（14例，14例未产）。无核参与者从未生过孩子。在数据收集之前的1至5年间，同卵参与者至少分娩了一个足月婴儿（37-42周），没有并发症。进行参与者首选，快速和固定（1.4 m / s）步行速度的运动捕捉。进行重复测量方差分析以测试关节运动学和动力学方面的显着组差异。

结果

该组有显着的主要影响，表明脚趾弯曲时膝部屈曲角度较大（p = 0.0002），脚跟打击时膝部伸展力矩较小（p = 0.0006），第一峰值膝关节屈曲力矩较小（p = 0.040）和较小与未产卵组相比，产卵组的最大髋关节内收力矩峰值（p = 0.003）。组之间的静态Q角没有差异。

意义

从惯常的装载方式改变力学被认为会增加OA的风险。产后妇女的膝关节力矩较小可能会改变对软骨的机械刺激，因此应结合软骨健康措施进行研究，以确定与OA引发的联系。