Shoulder Joint Overview

The shoulder joint has the widest range of motion more than any other joint in your body. This joint is actually a complex set of bones and soft tissue.

Bones overview

The humerus (upper arm) and the scapula (shoulder blade) are the two largest bones of the shoulder joint.


The humerus is also known as the upper arm bone.

Humorus head

The head portion of the humerus bone is covered by smooth cartilage, which glides over the shoulder joint cavity.


The scapula, or shoulder blade, is the large triangular bone located on the back side of the upper body.


This shallow cavity in the scapula is where the humerus head is inserted.


The acromion projects forward from the top of the scapula to form the “roof” of the shoulder.


The clavicle, also called the collarbone, attaches the shoulder to the rib cage and holds the shoulder out from the body.

Acromioclavicular joint

The AC joint connects the acromion and clavicle bones. The ends of the bones are covered with cartilage, which allows smooth movement and protects the bones.

Coracoid process

The coracoid process and the acromion form the "roof" of the shoulder. The coracoid process, acromion and glenoid form the socket in which the humerus head is cradled.

Soft tissue

Several ligaments make up the shoulder’s stabilizing joint capsule. Other soft tissue helps the joint flex and move with ease.

Rotator cuff

The rotator cuff muscles and tendons raise and lower the arm from the side. The rotator cuff also helps stabilize the shoulder joint by holding the humeral head in the socket.

Biceps tendon

The biceps tendon connects to the biceps muscle to the humorous. Muscles move bones by pulling on these tendons.


Between the rotator cuff muscles and the larger surrounding muscles lies the bursa. This is pocket of lubricating fluid allow muscles to move freely over each other.


The labrum, a ring of fibrous cartilage, surrounds the glenoid in the scapula. It helps attach the head of the humerus to the scapula.