Persons with patellofemoral pain exhibit altered hip abductor muscle recruitment while performing hip abductor exercises.
Level 4 - case-series / case-control
Cross-sectional case-control physiological study comparing symptomatic individuals to pain-free controls.
PubMed 35880404 · doi:10.1080/09593985.2022.2101167
What was done
Fine-wire electromyography (EMG) of the gluteus medius (GMED), superior gluteus maximus (SUP-GMAX), and tensor fascia lata (TFL) was measured in 32 participants (12 with patellofemoral pain [PFP], mean age 29.7 years; 20 controls without PFP, mean age 28.1 years) during the performance of 11 hip abductor exercises. Normalized EMG activity (% maximum voluntary isometric contraction, MVIC) was compared between groups.
What was found
Averaged across all 11 exercises, the PFP group exhibited significantly higher TFL activity (mean 25.3% MVIC; 95% CI 19.2 to 31.3) compared with controls (mean 17.6% MVIC; 95% CI 12.8 to 22.4) and significantly lower SUP-GMAX activity (mean 16.4% MVIC; 95% CI 11.0 to 22.0) compared with controls (mean 25.4% MVIC; 95% CI 21.0 to 29.8). GMED activation was lower in the PFP group for 3 out of 11 exercises (hip abduction, hip hike, and step-up) but not across the combined set.
Why it matters
Standard rehabilitation protocols frequently prescribe hip abductor strengthening for patellofemoral pain, but altered recruitment patterns (compensatory TFL dominance over gluteal musculature) during these exercises may undermine therapeutic goals if not addressed.
Limits
The sample size is small (12 cases, 20 controls), limiting statistical precision. The cross-sectional design cannot establish whether altered muscle recruitment is a cause or an adaptive consequence of patellofemoral pain. Clinical outcomes, pain levels during exercise, and the effects of corrective movement training were not evaluated.
Cited by
- supports Hip abduction movements specifically target and activate the gluteus medius and the upper fibers of the gluteus maximus.