Muscle function of the lower limb—Do we really test what we are looking for?

Established measures of lower‐limb muscle function repeatedly show weak, inconsistent or absent association and predictive value for injury, re‐injury and other musculoskeletal complaints. Progress in prevention, rehabilitation, and return‐to‐sport decision‐making is unlikely to come from recombining or modifying them. The question is whether the quantity they capture is unsuitable—calling for a change in what is measured. Muscle‐function assessment should match the demand it sets out to capture: non‐contact injuries occur when muscles must stabilise a joint and adapt to a rising external load. This adaptive, stabilising control is largely unaddressed by established measures. Shifting the focus from muscle strength to muscle stability—from producing force against a resistance to holding a position while adapting to a rising external load (Adaptive Force)—may bring assessment closer to what actually determines joint protection and clinical outcome.