Scapula:A flat, triangular bone located on the posterior side of the ribcage that forms part of the shoulder girdle.
Glenohumeral joint: The ball-and-socket joint between the head of the humerus (upper arm bone) and the glenoid cavity of the scapula, allowing a wide range of shoulder movements.
Teres major muscle: A muscle attached to the lateral border of the scapula that plays a crucial role in rotating and adducting (moving towards) the humerus