Final answer:
The rectus femoris originates from the anterior inferior iliac spine of the ilium, which is part of the pelvic girdle, and it inserts into the patella and the tibia via the patellar ligament.
Step-by-step explanation:
The rectus femoris muscle originates from the ilium. Specifically, it originates from the anterior inferior iliac spine of the ilium, which is part of the pelvic girdle. The rectus femoris is one of the four quadriceps muscles that extend the leg at the knee joint. The muscle has two heads: the direct head and the reflected head.
The direct head originates from the anterior inferior iliac spine while the reflected head originates from the ilium above the acetabulum. These strong muscle fibers converge into a single tendon that inserts into the patella, and via the patellar ligament, to the tibial tuberosity of the tibia.