Human leg the anterior superior iliac spine to the pes anserinus on the medial side of the knee, from where it is further extended into the crural fascia. The sartorius acts as a flexor on both the hip and knee, but, due to its oblique course, also contributes to medial rotation of the leg as one of the pes anserinus muscles (with the knee flexed), and to lateral rotation of the hip joint. There are four posterior thigh muscles. The biceps femoris has two heads: The long head has its origin on the ischial tuberosity together with the semitendinosus and acts on
Mechanoreceptor frequency range generated upon finger tips by textures made of features smaller than 200 micrometres. The knee jerk is the popularly known stretch reflex (involuntary kick of the lower leg) induced by tapping the knee with a rubber-headed hammer. The hammer strikes a tendon that inserts an extensor muscle in the front of the thigh into the lower leg. Tapping the tendon stretches the thigh muscle, which activates stretch receptors within the muscle called muscle spindles. Each muscle spindle consists of sensory nerve endings wrapped around special muscle fibers called spindle fibers (also called intrafusal fibers). Stretching a spindle fiber