Background: Patellofemoral pain (PFP) is a common orthopedic problem, accounting for 25-40% of all knee problems addressed in sports medicine clinics. Improvement of treatment outcomes requires a better understanding of the condition’s etiology and the various treatment strategies. Recent literature on PFP has drawn attention to the importance of hip strength, in particular for the hip abductor and external rotator muscles, in controlling excessive valgus forces at the knee. Muscle damage associated with unaccustomed eccentric exercise can result in the formation of a myofascial trigger point (MTrP) and may cause muscle weakness. The purpose of this study was to: 1) determine the prevalence of MTrPs in the gluteus medius (GMe) for subjects with PFP, as compared to control, 2) examine the relationship between MTrPs and force production of the examined muscles, and 3) determine if trigger point pressure release therapy (TPPRT) and self-management techniques for MTrPs and GMe muscles will result in increased hip abduction strength in subjects with and without PFP. Methods: 60 subjects participated in this study, 30 with PFP and 30 non-PFP controls. All subjects were evaluated for the presence of MTrPs in the GMe muscles and hip abduction strength. Additionally, PFP subjects’ strength was measured after either a sham treatment or trigger point pressure release therapy (TPPRT). PFP subjects were reevaluated after a two-week interval for MTrPs and hip abduction strength. Results: Prevalence of bilateral GMe MTrPs for the PFP group was significantly higher compared to controls. The prevalence of MTrPs in bilateral GMe muscles in the PFP group made it difficult to determine if direct relationships existed between MTrPs and force production, however subjects in the PFP group displayed significantly less hip abduction force production between PFP treatment and sham groups were noted. Conclusions: Subjects with PFP have a higher prevalence of MTrPs in bilateral GMe muscles. PFP subjects demonstrate less hip abductor strength with strength compared to controls. No difference was found in hip abductor strength with TPPRT and sham at a two-weel follow-up.
