Anatomy Guide › Thorax
Clavicle
Run a finger along the top of your chest from the base of your throat toward your shoulder and you will trace the clavicle, or collarbone — an elegant S-shaped strut lying just under the skin. It is easy to overlook how unusual it is: the clavicle is the only bone that joins the upper limb to the axial skeleton. Every push-up, pull-up, and throw transmits force from your arm through the clavicle into your sternum.
The bone works like the spreader bar of a sail rig, holding the shoulder out to the side so the arm can swing clear of the trunk. Animals that don't need that range — horses, dogs — have reduced or absent clavicles. Ours is robust, but its position makes it vulnerable: a fall onto the shoulder or an outstretched hand drives force straight along its curve, and the bone tends to snap at the junction of its middle and outer thirds. Clavicle fractures are among the most common broken bones at every age, from newborns (during delivery) to cyclists.
The clavicle is also a landmark for what lies beneath. Immediately behind and below it run the subclavian artery and vein and the brachial plexus — the great nerve network of the arm. That is why the hollow above the collarbone matters to clinicians, and why displaced fractures occasionally threaten these structures.
It is also a developmental oddity: the clavicle is the first bone in the embryo to begin hardening, yet one of the last to finish, with its inner growth plate fusing in the mid-twenties — a fact forensic scientists use to estimate age. In Anamo, the clavicle is a superb anchor guess between the neck, chest, and shoulder regions: whatever the mystery part nearby, the collarbone's heat reading points the way.
- The only bone linking the arm to the axial skeleton
- One of the most commonly fractured bones in the body
- The subclavian vessels and brachial plexus pass directly beneath it
- First bone to start ossifying in the embryo, one of the last to finish
Think you could find the clavicle on a 3D model? Play Anamo and test yourself — every guess is color-coded by how close it lands to the mystery structure.