Unlike the vastus muscles, which cross only the knee joint, the rectus femoris muscle crosses both the hip and the knee joints (Fig. 6.59).
The rectus femoris has two tendinous heads of origin from the pelvic bone: one from the anterior inferior iliac spine (straight head), and the other from a roughened area of the ilium immediately superior to the acetabulum (reflected head) (Fig. 6.59).