Prevalence of myofascial trigger points in the hip in patellofemoral pain.

OBJECTIVES To determine the prevalence of myofascial trigger points (MTrPs) in the gluteus medius (GMe) and quadratus lumborum (QL) for subjects with patellofemoral pain (PFP), and to examine the relationship between MTrPs and force production of the GMe after treatment. DESIGN Randomized controlled trial. SETTING A physical therapy clinic. PARTICIPANTS Subjects (N=52; mean age ± SD, 30±12y; mean height ± SD, 172±10cm; mean mass ± SD, 69±14kg) volunteered and were divided into 2 groups: a PFP group (n=26) consisting of subjects with PFP, and a control group (n=26) with no history of PFP. INTERVENTIONS Patients with PFP received trigger point pressure release therapy (TPPRT). MAIN OUTCOME MEASURES Hip abduction isometric strength and the presence of MTrPs. RESULTS Prevalence of bilateral GMe and QL MTrPs for the PFP group was significantly higher compared with controls (P=.001). Subjects in the PFP group displayed significantly less hip abduction strength compared with the control group (P=.007). However, TPPRT did not result in increased force production. CONCLUSIONS Subjects with PFP have a higher prevalence of MTrPs in bilateral GMe and QL muscles. They demonstrate less hip abduction strength compared with controls, but the TPPRT did not result in an increase in hip abduction strength.