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
Leg raise in this movement by using the lats and other muscles to perform shoulder extension. The demands of force on the muscles can be increased through altered posture or apparatus. Extending the knee joint (often called a straight leg raise) increases the demands of leverage on both hip and spine flexors. It also allows the rectus femoris muscle to contribute, for both the supine straight leg raise and the hanging straight leg raise versions, although the muscle will be in active insufficiency in the latter case. The generic term "leg raise" usually indicates a bended knee, though the term "knee raise"