Your shoulder is the most mobile joint in your body, allowing an incredible range of motion for reaching, lifting, and throwing. This flexibility comes from a complex system of bones, muscles, tendons, and ligaments working together.

Understanding your shoulder's anatomy helps you recognize how injuries occur and why certain treatments are recommended. Dr. Albersheim specializes in advanced shoulder surgery, from arthroscopic repairs to joint replacement.

The Shoulder's Bone Structure

Three bones create your shoulder joint: the humerus (upper arm bone), scapula (shoulder blade), and clavicle (collarbone). The rounded head of the humerus fits into the shallow socket of the scapula, forming a ball-and-socket joint.

This shallow socket design allows for exceptional mobility but requires strong soft tissue support for stability. The clavicle connects your shoulder to your sternum, providing a stable base for arm movement.

The Rotator Cuff

Four muscles and their tendons form the rotator cuff, surrounding the shoulder joint like a cuff on a shirt sleeve. These muscles—the supraspinatus, infraspinatus, teres minor, and subscapularis—work together to stabilize the shoulder and enable rotation.

Rotator cuff tears are among the most common shoulder injuries, often resulting from overuse, falls, or age-related degeneration. The tendons can develop partial or complete tears that limit your ability to lift and rotate your arm.

The Labrum and Shoulder Stability

A ring of fibrous cartilage called the labrum lines the shoulder socket, deepening it and providing crucial stability. The labrum also serves as an attachment point for ligaments and the biceps tendon.

Labral tears can occur from shoulder dislocations, falls on an outstretched arm, or repetitive overhead motions. These injuries often cause pain, clicking sensations, and feelings of instability.

Ligaments and Joint Capsule

Multiple ligaments reinforce the shoulder joint capsule, providing passive stability while allowing the remarkable range of motion. The glenohumeral ligaments prevent excessive translation of the humeral head, while the coracohumeral ligament supports the rotator cuff.

Movement and Power

Beyond the rotator cuff, larger muscles like the deltoid, pectoralis major, and latissimus dorsi generate the power for shoulder movement. The deltoid forms the rounded contour of your shoulder and is responsible for lifting your arm away from your body, while the chest and back muscles enable pushing, pulling, and rotation.