Effects of Hip Muscle Strengthening on Pain and Health Status in Females with Patellofemoral Pain

This is the authors' abstract. We don't add key points for this paper.

Patellofemoral pain (PFP) is the most common overuse injury in runners. Hip muscle weakness has been proposed as a contributing factor with respect to the development of PFP. To date, the effects of isolated hip muscle strengthening on pain and health status in females with PFP has not been examined. PURPOSE: To examine the effectiveness of an 8 week hip strengthening program on pain and health status in females with PFP. METHODS: Twenty-eight females with bilateral PFP were sequentially assigned to an exercise (n=14) or control group (n=14). The exercise group completed bilateral hip abductor and external rotator strengthening 3 times per week for 8 weeks. Pain (VAS: 0-10 cm) and health status (WOMAC: 0-96) were assessed at baseline and at 8 weeks. Pain and health status also were evaluated at 6 months in the patients assigned to the exercise group. Independent t-tests were used to examine between group differences at baseline. Separate 2 × 2 ANOVAs with repeated measures were used to determine the effects of the intervention on all outcome variables. RESULTS: Demographic, pain, and health status were not different between groups at baseline (p>0.05). A significant main effect for time and interaction were present for pain and health status measures at 8 weeks (p <0.05). Pain and health status improved in the exercise group but did not change in the control group (VAS: -6.4 ± 2.7 vs. 0.1 ± 1.7 cm; WOMAC: -43.3 ± 20.1 vs. 4.1 ± 10.3). At 6 month follow-up, pain and health status of the exercise group was not different from that reported post-intervention (p>0.05). CONCLUSIONS: Hip abductor and external rotator strengthening was effective in improving pain and health status in females with PFP. Importantly, the improvements were sustained at the 6 month follow-up. Hip strengthening should be considered a viable intervention for patients with PFP.