Shoulder Joint Anatomy

The shoulder joint is a ball-and-socket joint that connects the upper arm bone (humerus) to the shoulder blade (scapula). The rounded head of the humerus fits into a shallow cavity called the glenoid, providing a wide range of motion. Surrounding the joint are ligaments and muscles, forming the rotator cuff, which stabilizes and enables movement. Key bones include the clavicle (collarbone) and scapula, while tendons connect muscles to bones. This intricate structure allows for activities like lifting, throwing, and reaching, making the shoulder one of the most mobile yet vulnerable joints in the body.