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Portrait of Clavicle

Anatomy · Bones

Clavicle

The collarbone

Pectoral girdle · shoulder

The clavicle, or collarbone, is a slender S-shaped bone that lies across the front of the shoulder, running from the breastbone to the tip of the shoulder blade. It is the only long bone that lies horizontally, and it acts as a strut that holds the shoulder joint out from the trunk. It is the most commonly fractured bone in the body.

How to spot them

  • ▸A slender rod, gently S-curved, lying horizontally across the top of the chest and palpable along its whole length
  • ▸Inner (sternal) end is triangular and meets the manubrium; outer (acromial) end is flattened and meets the acromion
  • ▸Curves forward at the inner end and backward at the outer end when viewed from above
  • ▸Its only bony link between the upper limb and the axial skeleton is the joint at its inner end

What to know

The only long bone in the body that lies in a horizontal position

Clavicle — the collarbone, a horizontal strut between sternum and shoulder.

Its inner end forms the sole bony joint connecting the whole arm to the skeleton of the trunk

Clavicle — the sternoclavicular joint is the only bony articulation between the pectoral girdle and the axial skeleton.

The bone most often broken in the body, usually in its middle-to-outer third after a fall onto an outstretched hand or a blow to the shoulder

Clavicle — the most commonly fractured bone.

A strut that holds the shoulder joint out and away from the chest wall, running from the top of the breastbone to the tip of the shoulder

Clavicle — it braces the scapula and transmits forces from the arm to the sternum.

In cleidocranial dysplasia this bone may be missing or underdeveloped, so that the shoulders can be brought together in front of the chest

Clavicle — 'cleido-' is the medical prefix for this bone.

Usually described as the first bone in the body to begin ossifying in the embryo, at about five to six weeks

Clavicle — it begins to ossify earlier than any other bone.

Its Latin name means 'little key'

Clavicle — from clavicula, a diminutive of clavis, a key.

Key ideas

  • It is a strut: braced by muscle from above, it holds the scapula and shoulder joint out from the trunk, giving the arm its wide range of movement.
  • Force from a fall on the hand travels up the arm to the shoulder; because the joint at its inner end is strong and rarely dislocates, the bone itself breaks, usually between its middle and lateral thirds.

Quick-fire facts

  • •It lies immediately under the skin along its whole length, so you can trace it with a finger from the notch at the base of the neck to the point of the shoulder.
  • •Its inner end articulates with the manubrium of the sternum (sternoclavicular joint) and its outer end with the acromion of the scapula (acromioclavicular joint).
  • •The subclavian vessels and the brachial plexus run behind it on their way from the neck to the arm; because a broken clavicle is pulled forward these structures are rarely injured.
  • •In a complete break the shoulder and outer fragment drop under the weight of the arm and are pulled forwards and inwards by the muscles, so the fragments override.
  • •Male clavicles tend to be longer, heavier and more curved than female ones, and more so in manual workers.
  • •The growth plate at its inner end is among the last in the body to fuse, in the early to mid-twenties, so it is used in estimating age.
  • •The word 'clavicle' comes from Latin clavicula, 'little key'; it is sometimes said to refer to the way the bone rotates on its long axis, like a key in a lock, when the arm is raised.

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