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
Aponeurosis of the abdominal external oblique muscle Aponeurosis of the abdominal external oblique muscle The aponeurosis of the abdominal external oblique muscle is a thin but strong membranous structure, the fibers of which are directed downward and medially. It is joined with that of the opposite muscle along the middle line, and covers the whole of the front of the abdomen; above, it is covered by and gives origin to the lower fibers of the pectoralis major; below, its fibers are closely aggregated together, and extend obliquely across from the anterior superior iliac spine to the pubic tubercle and the pectineal line. In the middle line, it