Appendicular Skeleton
Learn the shoulder girdle, arms, pelvic girdle, and legs that make up the body's limbs.
The skeleton of movement
The appendicular skeleton includes the bones of the arms and legs along with the girdles that attach them to the axial skeleton. Its 126 bones are built for a wide range of motion rather than heavy protection.
The appendicular skeleton, highlighted
The appendicular skeleton includes the pectoral and pelvic girdles along with the bones of the upper and lower limbs.
Shoulders
The clavicle and scapula attach the arms to the axial skeleton and allow a wide range of shoulder motion.
Arms and hands
The humerus, radius, ulna, and the many small bones of the wrist and hand make fine motor control possible.
Hips
The pelvis attaches the legs to the axial skeleton and helps support the weight of the upper body.
Legs and feet
The femur, tibia, fibula, and the bones of the foot bear weight and enable walking and running.
Built for a trade-off
Compared to the axial skeleton, the appendicular skeleton trades some protection for mobility, with joints like the shoulder and hip designed to allow a large range of motion.
Working with the axial skeleton
The appendicular and axial skeletons are not independent; the girdles physically link the limbs to the body's core so that forces generated by the limbs can be transferred through the trunk.
Mobility depends on a stable core.
Every movement of an arm or leg relies on the axial skeleton providing a stable base for the appendicular skeleton to move against.