Group XIII.Extension of hip and flexion of knee; outward and inward rotation of flexed knee; acting with rectus femoris and sartorius (see XIV, 1, 2) synchronizing simultaneous flexion of hip and knee and extension of hip and knee by belt-over-pulley action at knee joint.(1) Biceps femoris; (2) semimembranosus; (3) semitendinosus Function: Posterior thigh group, Hamstring complex of 2-joint muscles

VA disability rating criteria for Group XIII.Extension of hip and flexion of knee; outward and inward rotation of flexed knee; acting with rectus femoris and sartorius (see XIV, 1, 2) synchronizing simultaneous flexion of hip and knee and extension of hip and knee by belt-over-pulley action at knee joint.(1) Biceps femoris; (2) semimembranosus; (3) semitendinosus Function: Posterior thigh group, Hamstring complex of 2-joint muscles under Diagnostic Code 5313. The VA assigns ratings of 0%, 10%, 30%, 40% based on the severity and functional impact of your condition.