Background

Deficits in knee flexor strength and rate of torque development (RTD) might be present in women with patellofemoral pain (PFP). In addition, maximal strength and RTD of the knee flexors and extensors might be related with subjective and objective function in women with PFP. However, both conjectures are still poorly understood.

Research question

Do women with PFP have deficits in the maximal strength and RTD of the knee flexors and extensors during isometric, concentric, and eccentric contractions? Is there a relationship between maximal strength and RTD of the knee flexors and extensors with subjective and objective function in women with PFP?

Methods

Fifty-six women with, and 46 women without, PFP participated. Maximal strength and RTD (to 30% and 60% maximal torque) during isometric, concentric, and eccentric contractions of the knee flexors and extensors were assessed using an isokinetic dynamometer. Objective assessment included single leg hop test (SLHT) and forward step-down test (FSDT). Subjective assessment involved the anterior knee pain scale.

Results

Women with PFP had small to large deficits in maximal strength and RTD of the knee flexors and extensors during isometric, concentric and eccentric contractions (Effect sizes: -0.43 to -1.10; p ≤ 0.016). Small to moderate correlations of maximal concentric and eccentric knee flexor strength and RTD with SLHT and FSDT (r = 0.28 to 0.41; p ≤ 0.037) were identified. Subjective or objective function were not correlated with maximal isometric knee flexor strength and RTD, or any knee extensor measures (p > 0.05).

Significance

Maximal strength and RTD deficits of the knee flexors and extensors were identified in this female PFP cohort, but they were unrelated to subjective function. The relationship of concentric and eccentric knee flexor strength and RTD deficits with poor objective function should be considered in future exercise trials for women with PFP.

中文翻译：

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tell股股骨疼痛妇女的膝屈肌力量和扭力发育障碍率与客观功能差有关

背景

tell股股骨疼痛（PFP）的女性可能存在膝屈肌力量和扭矩发展率（RTD）不足。此外，PFP妇女的膝关节屈伸肌的最大力量和最大运动阻力可能与主观和客观功能有关。但是，这两个推测仍然知之甚少。

研究问题

患有PFP的女性在等距，同心和偏心收缩过程中，膝关节屈肌和伸肌的最大力量和RTD是否存在缺陷？PFP女性膝关节屈肌和伸肌的最大力量与RTD的关系是否具有主观和客观功能之间是否存在关系？

方法

有PFP的56名妇女和46名无PFP的妇女参加了会议。使用等速测功机评估膝关节屈伸肌的等长，同心和偏心收缩过程中的最大强度和RTD（分别达到最大扭矩的30％和60％）。客观评估包括单腿跳跃测试（SLHT）和前降压测试（FSDT）。主观评估涉及前膝关节疼痛量表。

结果

患有PFP的女性在等距，同心和偏心收缩过程中，膝关节屈肌和伸肌的最大力量和RTD均存在小到大的缺陷（效应量：-0.43至-1.10； p≤0.016）。可以确定最大同心和偏心膝盖屈肌力量与RTD与SLHT和FSDT的相关性较小（中度）（r = 0.28至0.41； p≤0.037）。主观或客观功能与最大等距膝盖屈肌力量和RTD或任何膝关节伸肌测量值均无相关性（p > 0.05）。

意义

在该女性PFP队列中，已确定膝屈肌和伸肌的最大力量和RTD缺陷，但它们与主观功能无关。在PFP妇女的未来运动试验中，应考虑同心和偏心屈肌力量和RTD缺乏与客观功能的关系。