Joint · Shoulders

Sternoclavicular joint

Articulatio sternoclavicularis

The only bony joint between the arm and the rest of the skeleton. The collarbone meets the top of the breastbone here, and a fibrocartilaginous disc sits between them, dividing the joint in two and absorbing force transmitted in from the arm. Every time you raise your arm, this small joint has to move — so although it is easy to overlook, it is an obligatory link in the chain. It is exceptionally stable: the disc and its strong ligaments make dislocation rare compared with the joint at the other end of the same bone.