Exploring the Relationship Between Gluteus Medius Activation and Pain Intensity in Patients With Patellofemoral Pain Syndrome: A Cross-Sectional Study

Background and Aims Patellofemoral pain syndrome (PFPS) is one of the most common causes of anterior knee pain, especially among physically active individuals and athletes. Dysfunction of the gluteus medius muscle, which plays a key role in hip stabilization and dynamic control of the lower extremity, has been identified as a biomechanical factor in patients with PFPS. This study aimed to investigate the relationship between the intensity of gluteus medius muscle activity and pain severity in patients with PFPS. Methods This cross-sectional descriptive-analytical study included 32 patients diagnosed with PFPS. Pain severity was measured using the visual analog scale (VAS), and gluteus medius activity was assessed by surface electromyography (EMG) during stair ascent and descent. EMG data were normalized to the maximum voluntary isometric contraction (MVIC). Both average and peak muscle activity were recorded. Data were analyzed using SPSS software, version 27 and the Pearson correlation test. Results The mean pain score was 4.83±1.18 cm. The mean activity of the gluteus medius during stair ascent and descent was 24.27±12.83% and 20.14±11.65% of MVIC, respectively. The peak activity was 54.59±31.31% and 50.77±28.67% during stair ascent and descent, respectively. The results showed a non-significant negative correlation between gluteus medius activity and pain severity. Conclusion Although the study found an inverse trend between gluteus medius activity and pain intensity, the relationship was not statistically significant. Strengthening the gluteus medius muscle may still be considered as part of a rehabilitation approach for PFPS, and further studies with larger sample sizes and control of confounding variables are recommended.