Human leg the femur. All four muscles unite in a common tendon inserted into the patella from where the patellar ligament extends it down to the tibial tuberosity. Fibers from the medial and lateral vasti form two retinacula that stretch past the patella on either sides down to the condyles of the tibia. The quadriceps is "the" knee extensor, but the rectus femoris additionally flexes the hip joint, and articular muscle of the knee protects the articular capsule of the knee joint from being nipped during extension. The sartorius runs superficially and obliquely down on the anterior side of the thigh, from
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"