The effect of additional strengthening and stretching of hip rotator muscles in patients with patellofemoral pain syndrome: A randomized controlled crossover study

Abstract

To evaluate the effect of hip external rotators and abductors strengthening in association with hip internal rotators stretching on pain and function in patients with Patellofemoral Pain Syndrome (PFPS). We conducted a cross-over randomized study including 109 patients with PFPS (75 females and 34 males aged of 31.6 ± 10.8 years). Patients were randomly assigned into first protocol A (G1, n = 67) of A-B arm with standard rehabilitation or protocol B (G2, n = 42) of B-A arm with standard rehabilitation associated to strengthening of hip external rotator and abductor musculature with stretching of hip internal rotators. Each protocol consisted of 3 sessions a week for 4 weeks. After a washout period corresponding to the recurrence of the same painful symptoms experienced by the patient rehabilitation programs were crossed-over. A visual analog scale (VAS) evaluating perceived pain, Functional Index Questionnaire (FIQ) and Kujala patellofemoral score were administered at baseline, at the end of each rehabilitation protocol and at 12 weeks after the completion of the second protocol for each group. Pain and function were significantly improved in both arms for the total population ( P < 0.001) until the last follow up. Protocol B provided a more significant improvement in terms of pain and function in G2 (VAS: P = 0.03; Kujala: P = 0.04) and G1 (VAS: P = 0.02; Kujala: P = 0.02). Associating strengthening of hip abductors and external rotators and stretching of hip internal rotators provided better outcome in terms of pain and function in patients with PFPS which was maintained until the end of the study.