Does the relative muscle activation of the vastus medialis, rectus femoris, and vastus lateralis, during the various activities, change in relation to the quadriceps angle?

The study included only 17 healthy female adults, so the findings cannot be applied to men or to people with patellofemoral pain. It measured muscle activation and alignment, not actual patellofemoral pain, lateral force on the kneecap, or treatment response. The correlations were cross-sectional, so they cannot show that a larger quadriceps angle caused the muscle activation change. Some important correlations were close to but did not reach the significance threshold, including vastus lateralis relative to vastus medialis in step-up and sit-to-stand, and rectus femoris relative to vastus medialis in squatting. The study did not test whether strengthening the vastus medialis changes these patterns or pain.

The authors declared no conflicts of interest. No funding source is stated in the supplied text.

Do not conclude that a larger quadriceps angle causes patellofemoral pain or that vastus medialis strengthening will prevent it. The study measured muscle activation in 17 healthy women, not patients with knee pain, and no treatment was tested.