The rectus femoris muscle has two tendinous origins, the direct or straight head, which arises from the anterior inferior iliac spine (AIIS), and the indirect or reflected head, which arises from the superior acetabular ridge and the posterolateral aspect of the hip joint capsule .

The two heads form a conjoined tendon.

The rectus femoris is the most commonly injured muscle of the quadriceps muscle group.

Proximal rectus femoris strains can occur at the junction of the conjoint tendon with the muscle belly.