Physical therapy alters recruitment of the vasti in patellofemoral pain syndrome

Med Sci Sports Exerc. 2002 Dec;34(12):1879-85. doi: 10.1097/00005768-200212000-00004.


Purpose: To investigate the effect of physical therapy treatment on the timing of electromyographic (EMG) activity of the vasti in individuals with patellofemoral pain syndrome (PFPS).

Methods: Sixty-five (42 female, 23 male) participants aged 40 yr or less (29.2 +/- 7.8 yr) diagnosed with PFPS. Participants were randomly allocated into physical therapy treatment (McConnell-based) or placebo groups. Treatment programs were standardized and consisted of six-treatment sessions over 6 wk. Vastus medialis oblique (VMO) and vastus lateralis (VL) EMG activity was recorded with surface electrodes during a stair-stepping task and onsets of EMG activity were measured pre- and post-treatment.

Results: Before treatment, the EMG onset of VL occurred before that of VMO in both participant groups. After physical therapy intervention, there was a reduction in symptoms, and this improvement was associated with a significant change in the time of onset of VMO EMG compared with that of VL in both phases of the stair-stepping task. After physical therapy treatment, the onset of VMO preceded VL in the eccentric phase and occurred at the same time in the concentric phase of the stair-stepping task. There was no change in time of EMG onset in the placebo group.

Conclusion: This study demonstrates that a "McConnell"-based physical therapy treatment regime for PFPS alters the motor control of VMO relative to VL in a functional task and this is associated with a positive clinical outcome.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Cohort Studies
  • Electromyography
  • Exercise Therapy*
  • Female
  • Femur / physiopathology*
  • Follow-Up Studies
  • Humans
  • Joint Instability / complications
  • Joint Instability / physiopathology
  • Knee Joint / physiopathology*
  • Locomotion / physiology
  • Male
  • Muscle Contraction / physiology*
  • Observer Variation
  • Pain / complications
  • Pain / physiopathology*
  • Pain Measurement
  • Patella / physiopathology*
  • Predictive Value of Tests
  • Statistics as Topic
  • Syndrome
  • Time Factors
  • Treatment Outcome