Ultrasound measures of muscle thickness may be superior to strength testing in adults with knee osteoarthritis: a cross-sectional study.

Ultrasound is a feasible method to assess muscle bulk of lower limb muscles in adults with knee OA, with high levels of interrater reliability, and correlates negatively with patient reported function. Compared with use of a hand held dynamometer to measure muscle function, ultrasound may be a superior modality.