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

Background: Evaluation of muscle strength as performed routinely with a dynamometer may be limited by important factors such as pain during muscle contraction. Few studies have compared formal strength testing with ultrasound to measure muscle bulk in adults with knee osteoarthritis (OA).

Methods: We investigated the muscle bulk of lower limb muscles in adults with knee OA using quantitative ultrasound.