Ruhdorfer Anja, Wirth Wolfgang, Eckstein Felix
Institute of Anatomy, Paracelsus Medical University, Salzburg and Nuremberg, Salzburg, Austria.
Arthritis Care Res (Hoboken). 2015 Apr;67(4):509-18. doi: 10.1002/acr.22488.
To determine the relationship between thigh muscle strength and clinically relevant differences in self-assessed lower leg function.
Isometric knee extensor and flexor strength of 4,553 Osteoarthritis Initiative participants (2,651 women and 1,902 men) was related to the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) physical function scores by linear regression. Further, groups of male and female participant strata with minimum clinically important differences (MCIDs) in WOMAC function scores (6 of 68 units) were compared across the full range of observed values and to participants without functional deficits (WOMAC score 0). The effect of WOMAC knee pain and body mass index on the above relationships was explored using stepwise regression.
Per regression equations, a 3.7% reduction in extensor strength and a 4.0% reduction in flexor strength were associated with an MCID in WOMAC function in women, and, respectively, a 3.6% and 4.8% reduction in men. For strength divided by body weight, reductions were 5.2% and 6.7%, respectively, in women and 5.8% and 6.7%, respectively, in men. Comparing MCID strata across the full observed range of WOMAC function confirmed the above estimates and did not suggest nonlinear relationships across the spectrum of observed values. WOMAC pain correlated strongly with WOMAC function, but extensor (and flexor) muscle strength contributed significant independent information.
Reductions of approximately 4% in isometric muscle strength and of 6% in strength per body weight were related to a clinically relevant difference in WOMAC functional disability. Longitudinal studies will need to confirm these relationships within persons. Muscle extensor (and flexor) strength (per body weight) provided significant independent information in addition to pain in explaining variability in lower leg function.
确定大腿肌肉力量与自我评估的小腿功能临床相关差异之间的关系。
通过线性回归分析，对4553名骨关节炎倡议参与者（2651名女性和1902名男性）的等长伸膝和屈膝力量与西安大略和麦克马斯特大学骨关节炎指数（WOMAC）身体功能评分进行关联分析。此外，对WOMAC功能评分存在最小临床重要差异（MCID，68分制中的6分）的男性和女性参与者分层组，在整个观察值范围内进行比较，并与无功能缺陷的参与者（WOMAC评分为0）进行比较。使用逐步回归分析探讨WOMAC膝关节疼痛和体重指数对上述关系的影响。
根据回归方程，女性伸肌力量降低3.7%、屈肌力量降低4.0%与WOMAC功能的MCID相关，男性分别为降低3.6%和4.8%。对于力量除以体重，女性分别降低5.2%和6.7%，男性分别降低5.8%和6.7%。在WOMAC功能的整个观察范围内比较MCID分层证实了上述估计，并且未表明在观察值范围内存在非线性关系。WOMAC疼痛与WOMAC功能密切相关，但伸肌（和屈肌）肌肉力量提供了重要的独立信息。
等长肌肉力量降低约4%，每体重力量降低6%与WOMAC功能残疾的临床相关差异有关。纵向研究需要在个体内部证实这些关系。除疼痛外，伸肌（和屈肌）力量（每体重）在解释小腿功能变异性方面提供了重要的独立信息。
