Shoulder Anatomy

 

Acromion

Roof of the shoulder blade

Acromio-Clavicular Joint (ACJ)

The joint where the clavicle (collar bone) connects to the roof of the shoulder blade (the acromion).

Bursa

A bursa is a fluid filled sack found around some joints in the body. A bursa acts as a cushion between the tendons, muscles and bones, reducing friction and allowing smooth movement.

Capsule

A fibrous tissue covering that encircle the joint.

Articular cartilage

Articular cartilage is a stiff but flexible connective tissue, present on the moving surfaces of joints. It enables bones in the joints to move against each other smoothly. It is more flexible than bone, but not as flexible as muscle. It has virtually no blood supply, so cannot be easily regenerated by the body.

Clavicle

Commonly known as the collarbone, the clavicle connects the shoulder and arm to the sternum (breast bone).

Glenohumeral Joint

The glenohumeral joint is the main joint of the shoulder, where the ball of the humerus meets the socket of the glenoid fossa of the shoulder blade.

Humerus

The humerus is the long bone in the arm that runs from shoulder to elbow, connecting the scapula with the lower arm.

Infraspinatus

One of the muscles in the rotator cuff group. Function: Externally rotates the arm.

Labrum

Fibrocartilage which sits on the rim of the glenoid fossa, creating a slightly deeper socket.

Ligament

A ligament is a fibrous tissue that connect bones to other bones in a joint. A ligament can be a re-enforcing part of a capsule and act to stabilise as joint, whilst allowing movement.

Rotator Cuff

The rotator cuff is the group of muscles and connecting tendons which help to move and stabilise the shoulder joint. The muscles making up the rotator cuff are: the supraspinatus, the infraspinatus, the teres minor and the subscapularis.

Scapula

Commonly known as the shoulder blade, the scapula connects the humerus with the clavicle.

Shoulder Blade

see Scapula

Subacromial Bursa

The bursa situated beneath the acromion.

Subscapularis

One of the muscles in the rotator cuff group. Function: Internally rotates the humerus.

Supraspinatus

One of the muscles in the rotator cuff group. Function: Elevates the arm.

Tendon

A tendon is a tough band of fibrous tissue that connect muscles to bone.

Tendon Sheath

Some tendons are surrounded by a membrane called a tendon sheath. This is filled with a gel-like fluid that lubricates the tendon, enabling it to move smoothly and elastically.

Teres Minor

One of the muscles in the rotator cuff group. Function: Externally rotates the arm.