Which action stabilizes the sternoclavicular joint (prevents dislocation)?

Which action stabilizes the sternoclavicular joint (prevents dislocation)?

• A. Pads brachial plexus and subclavian vessel
• B. Stabilizes sternoclavicular joint (prevents dislocation)
• C. Anchors and depresses scapula
• D. Elevates the clavicle

Answer: (B)

Stability of the sternoclavicular joint comes from its capsule and the surrounding ligaments that limit movement and keep the joint from dislocating. The costoclavicular ligament anchors the clavicle to the first rib and tightens when the medial end of the clavicle tries to rise, helping prevent dislocation. The interclavicular ligaments connect the two clavicles at the top of the sternum to resist downward splaying, and the anterior and posterior sternoclavicular ligaments reinforce the joint capsule to block forward and backward dislocations. An articular disc adds to congruence and stability during movement. Because the essential action here is preventing dislocation through these stabilizing structures, the option that describes stabilization as preventing dislocation best fits. The other choices either refer to protecting nearby neurovascular structures, moving the scapula, or elevating the clavicle, which do not capture how the joint is stabilized.

Stability of the sternoclavicular joint comes from its capsule and the surrounding ligaments that limit movement and keep the joint from dislocating. The costoclavicular ligament anchors the clavicle to the first rib and tightens when the medial end of the clavicle tries to rise, helping prevent dislocation. The interclavicular ligaments connect the two clavicles at the top of the sternum to resist downward splaying, and the anterior and posterior sternoclavicular ligaments reinforce the joint capsule to block forward and backward dislocations. An articular disc adds to congruence and stability during movement. Because the essential action here is preventing dislocation through these stabilizing structures, the option that describes stabilization as preventing dislocation best fits. The other choices either refer to protecting nearby neurovascular structures, moving the scapula, or elevating the clavicle, which do not capture how the joint is stabilized.