Final answer:
True, all shoulder movements involve the sternoclavicular joint because it facilitates the range of motion of the clavicle, which is connected to the scapula and affects its movements.
Step-by-step explanation:
The statement that "all shoulder movements involve the sternoclavicular joint" is true. This joint is the only bony articulation between the pectoral girdle of the upper limb and the axial skeleton. When shoulder movements occur, the clavicle moves in various directions such as upward/downward and anterior/posterior. The sternoclavicular joint is supported by the costoclavicular ligament, which spans from the sternal end of the clavicle to the first rib.
Furthermore, the lateral or acromial end of the clavicle articulates with the acromion of the scapula at the acromioclavicular joint, and the scapula also articulates with the humerus at the glenohumeral joint, which is known for having the largest range of motion of any joint in the body. In summary, while the scapula and clavicle articulate at different joints, movements at one directly impact the other due to the interconnectivity of the shoulder girdle.