Altered hip and trunk muscle function in individuals with patellofemoral pain
- Sallie M Cowan (s.cowan{at}unimelb.edu.au)
- Rehabilitation Sciences Research Centre, The School of Physiotherapy, The University of Melbourne, Australia
- Kay M Crossley (k.crossley{at}unimelb.edu.au)
- Department of Mechanical Engineering and The School of Physiotherapy, University of Melbourne, Australia
- Kim L Bennell (k.bennell{at}unimelb.edu.au)
- Centre for Health Exercise and Sports Medicine, The School of Physiotherapy, University of Melbourne, Australia
- Published Online First 6 October 2008
Abstract
Objective: The purpose of this study was to investigate the role of hip muscles in PFP, specifically by investigating neuromotor control, strength and range of motion of the hip muscles.
Design: cross-sectional.
Setting: University laboratory.
Patients: Ten participants diagnosed with PFP and 27 asymptomatic controls were recruited, using standard inclusion and exclusion criteria.
Main outcome measures: Electromyographic activity of the vasti and anterior gluteus medius were recorded using surface electrodes and posterior gluteus medius using fine wire electrodes while the participant completed a stair stepping task. Hip strength and trunk side flexion strength was assessed using a hand held dynamometer and hip range of motion with an inclinometer. Pain and disability measures were recorded for the PFP participants.
Results: When individuals with PFP completed the stair stepping task there was a delay in activation of both anterior and posterior gluteus medius (p<0.02) and an alteration in vasti control (p=0.001). In addition trunk side flexion strength was significantly less (29%) in individuals with PFP (p=0.03).
Conclusion: This study provides evidence that trunk side flexion strength and neuromotor control of the gluteus medius are affected in people with PFP. This study also confirms the presence of a delayed vastus medialis obliquus relative to vastus lateralis, providing further evidence underpinning the importance of retraining the vasti function in patients with PFP.
