Collar Bone

The collar bone, medically termed the clavicle, is a long, slender S-shaped bone extending horizontally between the sternum (breastbone) and the scapula (shoulder blade), forming part of the shoulder girdle. Each person has two clavicles, one on each side, easily felt beneath the skin in the upper chest area extending from the neck base toward the shoulders. The clavicle is one of the most frequently fractured bones in the human body, often injured during falls onto an outstretched hand or direct shoulder impacts in sports, accidents, or physical activities.

Functionally, the clavicle serves several important roles: it acts as a strut that holds the shoulder out from the body, allowing the arm to hang freely and move with greater range; it transmits force from the upper limb to the axial skeleton (supporting weight from arms through to the trunk); it protects underlying nerves and blood vessels that supply the arm and shoulder region; and it provides attachment points for numerous muscles of the chest, shoulder, and neck that control shoulder and arm movements. Clavicle fractures typically cause sharp pain, swelling, bruising, inability to lift the arm, and sometimes visible deformity or a bump where the fracture occurred. Treatment depends on fracture severity: simple fractures may heal with immobilization using a sling or figure-of-eight bandage, while complex or displaced fractures might require surgical fixation with plates and screws. The clavicle is notable as the first bone to begin ossification (hardening) during fetal development and one of the last to complete growth (around age 25), making it vulnerable to injury across the lifespan. Its S-shape, with curves in horizontal and vertical planes, provides strength while minimizing weight. Understanding clavicle anatomy helps appreciate shoulder mechanics, recognize injury symptoms for prompt treatment, and comprehend how this seemingly simple bone plays a crucial structural role in upper body function and movement.