Scapula:A flat, triangular bone located in the upper back that connects with the clavicle at the front and with the humerus (arm bone) at its side.
Glenohumeral Joint:A ball-and-socket joint formed between the head of the humerus and the glenoid fossa of the scapula, allowing a wide range of motion for the arm.
Trapezius Muscle:A large superficial muscle that extends from the occipital bone to the lower thoracic vertebrae and out to both scapulae, playing a key role in moving, rotating, and stabilizing the scapula