Electromyographic biofeedback-controlled exercise versus conservative care for patellofemoral pain syndrome

Objective: To determine the effects of electromyographic biofeedback treatment in patients with patellofemoral pain syndrome. Design: Randomized controlled trial. Setting: A physical medicine and rehabilitation department in a research hospital of a university referral center. Patients: Sixty patients with patellofemoral pain syndrome. Patients were randomly placed into 2 groups: biofeedback group (ra = 30) and a control group (n = 30). Intervention: The biofeedback group received electromyographic biofeedback training and a conventional exercise program, whereas the control group received a conventional exercise program only. Main Outcome Measures: Maximum and mean contraction values of the vastus medialis and the vastus lateralis muscles were assessed with the biofeedback device. Pain and functional status of the patients were measured by a visual analog scale (VAS) and the Functional Index Questionnaire (FIQ), respectively. Results: Contraction values improved significantly at the end of the first month, compared with the pretreatment values in both groups. Mean contraction values in the biofeedback group of the vastus medialis muscles in all 3 monthly measurements; and the vastus lateralis muscles at the end of the first month, were significantly higher than those of the control group. Significant improvements were shown for both the VAS and the FIQ in both groups. Monthly follow-ups showed no VAS and FIQ differences between the groups. Conclusion: Electromyographic biofeedback treatment did not result in further clinical improvement when compared with a conventional exercise program in patients with patellofemoral pain syndrome.