Laboratory of Biomechanics and Motor Control (LABCOM), School of Science and Technology, Sao Paulo State University (UNESP), Presidente Prudente, Sao Paulo, Brazil; La Trobe Sport and Exercise Medicine Research Centre (LASEM), School of Allied Health, Human Services and Sport, La Trobe University, Bundoora, Victoria, Australia.
La Trobe Sport and Exercise Medicine Research Centre (LASEM), School of Allied Health, Human Services and Sport, La Trobe University, Bundoora, Victoria, Australia.
Gait Posture. 2021 Jan;83:100-106. doi: 10.1016/j.gaitpost.2020.10.011. Epub 2020 Oct 16.
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.
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?
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.
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).
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.
髌股疼痛（PFP）女性可能存在膝关节屈肌力量和扭矩发展速率（RTD）不足的情况。此外，膝关节屈肌和伸肌的最大力量和 RTD 可能与 PFP 女性的主观和客观功能有关。然而，这两种推测仍知之甚少。
PFP 女性在等长、向心和离心收缩时，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和 RTD 与主观和客观功能之间是否存在关系？
56 名 PFP 女性和 46 名非 PFP 女性参与了研究。使用等速测力仪评估膝关节屈肌和伸肌在等长、向心和离心收缩时的最大力量和 RTD（至 30%和 60%最大扭矩）。客观评估包括单腿跳测试（SLHT）和向前跨步下降测试（FSDT）。主观评估包括前膝疼痛量表。
PFP 女性在膝关节等长、向心和离心收缩时，膝关节屈肌和伸肌的最大力量和 RTD 存在小到大量的缺陷（效应大小：-0.43 至-1.10；p ≤ 0.016）。最大的向心和离心膝关节屈肌力量和 RTD 与 SLHT 和 FSDT 之间存在小到中度相关性（r = 0.28 至 0.41；p ≤ 0.037）。主观或客观功能与最大等长膝关节屈肌力量和 RTD 或任何膝关节伸肌测量值均无相关性（p > 0.05）。
在本女性 PFP 队列中发现了膝关节屈肌和伸肌的最大力量和 RTD 缺陷，但它们与主观功能无关。在未来针对 PFP 女性的运动试验中，应考虑到向心和离心膝关节屈肌力量和 RTD 缺陷与较差的客观功能之间的关系。
