The appendicular skeleton consists of the bones of the pectoral (shoulder) girdle, pelvic (hip) girdle, arms, legs, hands, and feet.

The patella is a sesamoid bone that sits within the quadriceps_femoris tendon. Its anterior surface is convex, rough and has a broad base. The posterior surface has two concave facets for articulation with the medial and lateral condyles of the femur.