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
Human leg In human anatomy, the lower leg is the part of the lower limb that lies between the knee and the ankle. The thigh is between the hip and knee and makes up the rest of the lower limb. The term lower limb or "lower extremity" is commonly used to describe all of the leg. This article generally follows the common usage. The leg from the knee to the ankle is called the "crus" or "cnemis" . The calf is the back portion, and the tibia or shinbone together with the smaller fibula make up the front of the lower leg.