[TA] hamstring muscle of posterior compartment of thigh; origin, long head (caput longum) from tuberosity of ischium, short head (caput breve) from lower half of lateral lip of linea aspera; insertion, head of fibula; action, flexes knee and rotates the flexed leg laterally; nerve supply, long head, tibial, short head, fibular. SYN: musculus biceps femoris [TA], biceps muscle of thigh, musculus biceps flexor cruris.