Effects of hip abductor and external rotators strengthening and quadriceps strengthening in females with patellofemoral pain syndrome: A comparative study

Introduction: Patellofemoral pain syndrome (PFPS) is one of the knee orthopedic disorders which is more prevalent among females and adolescents. Quadriceps weakness, vastus medialis oblique reflex latency, hip abductor and external rotator weakness leading to a wider Q-angle are considered as the main causes of the syndrome. The purpose of the present study was to compare the effects of isolated hip abductor and external rotator strengthening with quadriceps strengthening on the pain and function of female patients with PFPS.Materials and Methods: 26 females with PFPS were randomly assigned to either group 1 or group 2. Group 1 participated in hip abductor and external rotator strengthening exercises while group 2 underwent quadriceps strengthening 3 sessions a week for 8 weeks. Hand held dynamometer, VAS and WOMAC questionnaires were respectively used to measure the strength, pain and function at pre- and post-intervention. ANOVA with repeated measure was used for the statistical analysis of the data.Results: Both groups showed significant differences between pre- and post-intervention conditions regarding the strength, VAS, and WOMAC values (P ≤ 0.01). Post intervention comparison of VAS and WOMAC values between the two groups did not revealed any statistically significant difference (P ≤ 0.01).Conclusion: Pos- intervention of both groups (1 and 2) showed decreased pain and improved function and strength. However, no significant differences were found between these two groups at post-intervention. Based on the findings of the present study, both hip abductor and external rotator strengthening and quadriceps strengthening improved the pain and the function of patients with PFPS.Keywords: Patellofempral pain syndrome (PFPS), Hip abductor, External rotator and Quadriceps muscles, Strengthening, Quadriceps