Which bone in the leg is the kneecap?

• A. Tibia
• B. Femur
• C. Fibula
• D. Patella

Answer: (D)

The kneecap is the patella. It’s a small, flat bone sitting at the front of the knee, embedded in the quadriceps tendon as a sesamoid bone. This placement lets the patella act like a pulley, increasing the leverage of the quadriceps muscle so extending the knee becomes more efficient. The patella glides within a groove on the femur (the trochlear groove) as the knee flexes and extends, and its posterior surface is covered with cartilage to reduce friction against the femur. The other bones listed—tibia (shinbone), fibula (calf bone), and femur (thigh bone)—are not the kneecap.