STRENGTH AND MUSCLE ACTIVITY COMPARISONS OF WOMEN WITH AND WITHOUT PATELLOFEMORAL PAIN

Abstract

Patellofemoral pain (PFP) is a commonly occurring problem that is not well understood. However, it is thought to be related to decreased muscular control of the hip as it articulates with the pelvis, which can then be associated with faulty biomechanics at the knee. The purpose of the first study of this dissertation was to investigate and describe the hip strength and functional strength ratio profiles of women with PFP in comparison to women without PFP (N = 19). The purpose of the second study was to identify muscle activity patterns in four hip muscles in women with PFP in comparison to women without PFP (N = 21). The primary finding in the first study was that women with PFP had a higher ratio of concentric hip abduction strength to eccentric hip adduction strength than women without PFP. This would suggest that there was a decreased level of muscular control and stability at the hip in women with PFP compared to women without. This may be associated with compromised biomechanics that could be related to increased dynamic valgus at the knee. This dynamic valgus has been attributed to PFP by previous research. Future studies should focus on continuing to identify both conventional as well as functional strength ratio patterns in persons with PFP, and how these ratios relate to the biomechanical attributes of the condition. In the second study, the tensor fascia latae (TFL) was found to exhibit a higher level of muscle activity during several different functional movements in women with PFP when compared to women without PFP. It is thought that this higher level of activity may be related to a complex problem of decreased strength and activity in other muscle that stabilize the hip. It is possible that strengthening exercises that focus on increasing the strength of the external rotators of the hip as well as weight bearing stabilization exercises may improve symptoms in women with PFP. Future studies should focus on continued examination of muscle activity patterns in persons with PFP, including co-activation patterns and timing of activation.