Motion Orthopaedics logo
Dr. King Orthopedics, Saint Louis, Missouri
Shoulder Surgeon, Saint Louis, Missouri

Shoulder Anatomy


Shoulder Anatomy, Saint Louis, MissouriThe shoulder is a ball and socket joint with the greatest range of motion compared to any other joint in the body. The humeral head is the ball of the ball and socket joint, where the glenoid is the the socket. The socket is extremely small and shallow compared to the humeral head. This mismatch is essential to allow the amount and types of motion seen in this joint.

The scapulothoracic joint refers to the joint involving the shoulder blade, or scapula, and rib cage. This joint is extremely important in shoulder motion and functions. Elevation of the arm through the shoulder also involves rotation of shoulder blade in a specific ratio and pattern.


The labrum is a elastic cartilage structure the surrounds the shallow socket, effectively deepening the socket to help with stability of the joint. This structure is commonly torn in shoulder dislocations.

Ligaments and Capsule

The joint capsule and ligaments are structures that connect the ball to the socket. The different ligaments work in intricate patterns tightening and relaxing based on positions of the shoulders.

Rotator Cuff

The rotator cuff is a group of 4 muscles that originate on the shoulder blade and become thick tendons as the attach to the lateral aspect of the humeral head. The muscles are important in raising the arm above the shoulder, but their true function is to pull the head into the socket. This action stabilizes the shoulder and allows the other large muscles about the shoulder to act on the arm to raise it.

David J. King, M.D, Saint Louis, Missouri
David J. King, M.D, Saint Louis, Missouri
Femoro Acetabular Impingement FAI, Saint Louis, Missouri
Arthroscopic Hip Surgery, Saint Louis, Missouri
Bankart Repair Capsular Shift, Saint Louis, Missouri
Workers Compensation, Saint Louis, Missouri
Acetabular Labrum Repair, Saint Louis, Missouri
Hip Arthroscopy, Saint Louis, Missouri
American Hip Institute
Bookmark and Share
Dr. David King in Twitter Dr. David King in Facebook Dr. David King in Linked In Dr. David King in YouTube
Your Practice Online
Home | Disclaimer | Privacy | Sitemap | Feedback | Tell a friend | Contact Us
David J. King, M.D King Orthopedics Call Us: (314) 222-2773 ,1-888-998-KING