movements

Last reviewed 01/2018

The sternoclavicular joint acts as a ball and socket joint because it is capable of three degrees of freedom of movement:

• elevation and depression:
• the axis of rotation runs through the costoclavicular ligament
• the ligament acts as a fulcrum
• consequently, elevation of the lateral end of the clavicle is associated with the medial end moving downwards and laterally
• maximal depression of the lateral end of the clavicle is limited by tension in the costoclavicular ligament and the pull of the subclavius muscle
• depression of the medial end of the clavicle is limited by tension in the interclavicular ligament and by the interarticular disc
• the maximum range of movement is about 60 degrees

• protraction and retraction:
• again the axis of rotation is the costoclavicular ligament causing the medial end of the clavicle to move in the opposite direction to the lateral end
• at the extremes, movement is limited by the sternoclavicular and costoclavicular ligaments
• the total angular range of movement is 35 degrees

• axial rotation:
• possible due to the incongruous articular surfaces
• not brought about by direct muscular pull but rather by the movements of the scapula which are transferred to the clavicle by the action of the coracoclavicular ligaments
• the axis of rotation is through the centre of the articular surface
• the total angular range of movement is about 40 degrees