Sartorius muscle ilium, the ilio-pectineal line or the pubis. The muscle may be split into two parts, and one part may be inserted into the fascia lata, the femur, the ligament of the patella or the tendon of the semitendinosus. The tendon of insertion may end in the fascia lata, the capsule of the knee-joint, or the fascia of the leg. The muscle may be absent in some people. The sartorius muscle can move the hip joint and the knee joint, but all of its actions are weak, making it a synergist muscle. At the hip, it can flex, weakly abduct, and
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"