Jacquelin Perry Musculoskeletal Biomechanics Research Laboratory, Division of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, CA.
J Orthop Sports Phys Ther. 2014 May;44(5):320-7. doi: 10.2519/jospt.2014.4936. Epub 2014 Mar 27.
Single-group, repeated-measures design.
To compare patellofemoral joint (PFJ) stress among weight-bearing and non-weight-bearing quadriceps exercises.
An important consideration when prescribing exercises to strengthen the quadriceps in persons with patellofemoral pain is to minimize PFJ loading. Currently, there is disagreement in the literature as to which exercises and ranges of motion best accomplish this goal.
Ten healthy subjects participated. Lower extremity kinematics, kinetics, and electromyography of the knee musculature were obtained during a weight-bearing squatting exercise and 2 non-weight-bearing knee extension exercises: (1) knee extension with variable resistance, and (2) knee extension with constant resistance. A previously described biomechanical model was used to estimate PFJ stress at 0°, 15°, 30°, 45°, 60°, 75°, and 90° of knee flexion. PFJ stress was compared among the 3 exercises using a 2-way analysis of variance with repeated measures.
Compared to the 2 non-weight-bearing exercises, the squat exercise produced significantly higher PFJ stress at 90°, 75°, and 60° of knee flexion. Conversely, the 2 non-weight-bearing exercises produced significantly higher PFJ stress at 30°, 15°, and 0° of knee flexion when compared to the squat exercise. The knee-extension-with-variable-resistance exercise produced significantly lower PFJ stress than the knee-extension-with-constant-resistance exercise at 90°, 75°, and 60° of knee flexion.
To minimize PFJ stress while performing quadriceps exercises, our data suggest that the squat exercise should be performed from 45° to 0° of knee flexion and the knee-extension-with-variable-resistance exercise should be performed from 90° to 45° of knee flexion.
单组、重复测量设计。
比较负重和非负重股四头肌练习对髌股关节（PFJ）的压力。
在为髌股疼痛患者开具股四头肌强化运动时，一个重要的考虑因素是尽量减少 PFJ 负荷。目前，文献中对于哪些运动和运动范围最能达到这一目标存在分歧。
10 名健康受试者参与。在负重深蹲运动和 2 种非负重膝关节伸展运动期间，获得了下肢运动学、动力学和膝关节肌肉的肌电图：（1）可变阻力的膝关节伸展，（2）恒定阻力的膝关节伸展。使用先前描述的生物力学模型，在膝关节屈曲 0°、15°、30°、45°、60°、75°和 90°时估计 PFJ 应力。使用重复测量的 2 因素方差分析比较 3 种运动之间的 PFJ 应力。
与 2 种非负重运动相比，深蹲运动在膝关节屈曲 90°、75°和 60°时产生的 PFJ 应力明显更高。相反，2 种非负重运动在膝关节屈曲 30°、15°和 0°时产生的 PFJ 应力明显高于深蹲运动。与恒定阻力的膝关节伸展运动相比，可变阻力的膝关节伸展运动在膝关节屈曲 90°、75°和 60°时产生的 PFJ 应力明显更低。
为了在进行股四头肌练习时尽量减少 PFJ 应力，我们的数据表明，深蹲运动应在膝关节屈曲 45°至 0°之间进行，可变阻力的膝关节伸展运动应在膝关节屈曲 90°至 45°之间进行。
