The clavicle, commonly called the collarbone, is a long, S-shaped bone that runs horizontally across the top of your chest, just above the first rib. You have two of them, one on each side, and you can feel them easily under the skin. The clavicle is the only bony link between your arm and the rest of your skeleton, which makes it essential for shoulder movement and stability.
Where the Clavicle Sits and What It Connects
Each clavicle stretches from the center of your chest to the tip of your shoulder. On the inner end, it connects to your breastbone (the sternum), forming a joint you can feel at the base of your throat. On the outer end, it meets a bony projection at the top of your shoulder blade, forming the joint at the tip of your shoulder. These two joints anchor the clavicle in place and allow it to move slightly when you raise your arms or shrug your shoulders.
Together with the shoulder blade, the clavicle forms what’s called the pectoral girdle, the ring of bone that attaches your entire arm to your torso. Without it, your shoulder would have no rigid support and your arm would collapse inward toward your chest.
What the Clavicle Actually Does
The clavicle works like a strut or a brace. It holds your shoulder blade in position against your back so your arm can hang freely at your side. That strut action lets the shoulder blade glide smoothly along the ribcage, which is critical for full range of motion in your arm. Reaching overhead, throwing a ball, pushing a door open: all of these movements depend on the clavicle keeping your shoulder the right distance from your ribcage.
The bone also acts as a shield. Running directly beneath it are major blood vessels (the subclavian arteries, which supply blood to your arms) and a large network of nerves called the brachial plexus, which controls sensation and movement in your entire upper limb. The clavicle’s position provides a layer of bony protection over these structures.
Shape and Structure
If you look at a clavicle from above, it has a gentle S-curve. The inner half curves forward and the outer half curves backward. This shape gives the bone spring-like flexibility, letting it absorb some force from impacts to the shoulder rather than transmitting all of it to the chest.
The two ends look noticeably different. The inner end (closer to your throat) is rounded and thick, while the outer end (at your shoulder) is flatter and wider. Several muscles attach along its length, including muscles of the chest, neck, and upper back, which is why collarbone pain can sometimes radiate into nearby areas.
How the Clavicle Develops
The clavicle is one of the first bones in the body to start hardening during embryonic development. Two separate centers of bone formation appear as early as six weeks after conception and fuse together about a week later. Despite this early start, the clavicle is one of the last bones to finish growing. The inner end doesn’t fully fuse until the mid-20s in most people, which is why imaging of the clavicle is sometimes used to estimate age in young adults.
Clavicle Fractures: The Most Common Break
The clavicle is one of the most frequently broken bones in the body. Falls onto an outstretched hand, direct hits to the shoulder, and sports collisions are the usual causes. About 79% of clavicle fractures happen in the middle third of the bone, where it’s thinnest and has the least muscular support. Roughly 19% occur near the shoulder end, and fractures near the breastbone are rare, making up only about 1.4% of cases.
A broken clavicle typically causes sharp pain at the front of the shoulder, visible swelling, and sometimes a noticeable bump or deformity where the bone has shifted. It often hurts to lift the arm on the affected side, and many people instinctively cradle the injured arm against their body.
How Clavicle Fractures Heal
Most clavicle fractures heal without surgery. Treatment usually involves a sling to keep the arm still, pain management, and gradual return to movement as the bone knits together. Healing time varies significantly by age. Adults typically need 8 to 12 weeks. Adolescents heal faster, in roughly 6 to 8 weeks. Children under 8 may recover in 3 to 6 weeks, and infants can heal in as little as two weeks.
For fractures where the bone ends are significantly displaced or overlapping, surgery with a plate and screws may be recommended. A large review of studies found that surgery reduces the risk of the bone failing to heal (called non-union) from about 11.6% with non-surgical treatment to 1.4% with surgery. Symptomatic malunion, where the bone heals in a poor position causing ongoing problems, dropped from 11.3% to 1.2% with surgical repair.
Surgery does carry its own tradeoffs. About 10% of people who have a plate placed eventually need a second procedure to remove the hardware because of discomfort, and surgical infection occurs in roughly 3% of cases. For simple, well-aligned fractures, non-surgical treatment works well for the vast majority of people. The decision between the two approaches depends on how displaced the fracture is, how active you are, and your tolerance for a longer period of limited movement.