An apparatus for use in assessing strength of at least one knee flexor muscle of a subject, the apparatus including a support, two securing members, each securing member securing a respective lower leg of the subject in a position that in use is substantially fixed relative to the support and at least one sensor, which in use senses a force indicative of the strength of the at least one knee flexor muscle in at least one leg of the subject while the subject performs an eccentric contraction of the at least one knee flexor muscle.