home page impingement Fractures and Dislocations Shoulder Surgery Rehabilitation
The Shoulder Rotator Cuff Tears Shoulder Instability Find a Doctor Real-life Stories F.A.Q.


Shoulder bones

The two shoulder bones that form the golf ball and tee arrangement are the bone of the upper portion of the arm (called the humerus by doctors) and the shoulder blade, which is called the scapula. The ball-shaped end of the humerus rests in a shallow cup called the glenoid fossa and is located on the scapula. The ball on the top of the humerus is covered with a layer of surface cartilage, and so is the inside of the shallow cup of the glenoid. A small amount of joint fluid that is naturally produced by the body helps these two surfaces to glide on each other with hardly any friction. Strong ligaments that are called the joint capsule connect the ball and socket.


Shoulder diagram - Shoulder anatomy showing the shoulder bones.

The joint capsule allows the humerus to move freely in the glenoid and helps to prevent the shoulder from slipping out of joint. The shoulder blade has a curved section of bone called the acromion that extends from the back of the shoulder blade and curves over the top of the humeral head. This part of the scapula is joined to the collarbone (called the clavicle by doctors) at the acromio-clavicular, or A/C joint. The collarbone in turn attaches to the breastbone, or sternum, in the center of the chest. The collarbone plays an important role in helping to stabilize the entire shoulder and shoulder blade.

back to top | back to Shoulder Anatomy | next page



anteriorhipsurgery pediatric fractures hip fracture surgery sohrab gollogly md

© 2011 Carbon 12, LLC