The Relationship Between Gluteus Medius Activation And Pain Intensity during stair ascent and descent in Patient With Patellofemoral Pain Syndrome: a cross-sectional study

Document Type : Original article

Authors

1 Department of physiotherapy, school of rehabilitation, Shahid Beheshti university medical of science

2 physiotherapy, rehabilitation school of shahid beheshti university

3 Professor of Physiotherapy, School of Rehabilitation, Shahid Beheshti University of Medical Sciences, Tehran. Iran

10.22037/sjrm.2025.117438.3357

Abstract

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.



Materials and Method:

This cross-sectional descriptive-analytical study was conducted on 32 patients aged 18 to 40 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 analysis was performed using SPSS version 27 and 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 no significant correlation was found between gluteus medius activation intensity and pain severity in PFPS patients, the observed negative trend may suggest a potential role of this muscle in pain reduction. Therefore, solely focusing on strengthening may not be sufficient in rehabilitation, and incorporating various training approaches such as neuromuscular control, timing, power, and endurance could be more beneficial.

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Articles in Press, Accepted Manuscript
Available Online from 29 June 2025
  • Receive Date: 22 April 2025
  • Revise Date: 10 May 2025
  • Accept Date: 29 June 2025
  • First Publish Date: 29 June 2025