Anatomy of Shoulder Problems

By Chad Evans PT

Anatomy of Shoulder Problems

Working as a physical therapist in an outpatient rehab clinic, treating patients with various shoulder problems is fairly common. The majority of issues involve some level of dysfunction related to the soft tissue structures in the shoulder. Some issues are related to the bones and the anatomy of shoulder problems. To better understand common problems seen in the shoulder, it makes sense to discuss the shoulder’s anatomy.

Anatomy of Shoulder

Shoulder anatomy and Ligaments In The Shoulder


Shoulder Muscles

The shoulder has many different muscles that cross over the joint.  These muscles influence how the shoulder functions. They generate arm movement and provide dynamic stability to the shoulder joint.  They are the following:  Biceps, Triceps, Deltoids, Latissimus Dorsi, Pectoralis Major, Coracobracialis & Teres Major.  There are also the muscles called the Rotator Cuff (Supraspinatus, Infraspinatus, Subscapularis, and Teres Minor).

Shoulder Ligaments

The main ligaments that help connect the ball and socket joint are The glenohumeral ligaments and the coracohumeral ligaments. Another prominent ligament in the front of the shoulder is the transverse ligament.  These ligaments function to help provide stability by preventing separation of the bones they connect.

Shoulder Bones

Three bones comprise the shoulder.  The arm bone (humerus), the shoulder blade  (scapula), and the collar bone (clavicle).

Shoulder Joints

The shoulder joint is a ball and socket joint .  At the end of the arm, bone (humerus) is a ball-shaped structure known as the humeral head. It articulates with a socket-shaped indention on the side of the shoulder blade called the glenoid.

A second joint in the shoulder known as the acromioclavicular joint.  This joint is formed on top of the shoulder where the collar bone (clavicle) and acromion process (projection on the top portion of the scapula) meet.

Anatomy of Shoulder Problems- Common Injuries and Pathologies

Anatomy of Shoulder Problem after fall from bicycle

Shoulder injury after a bike accident

By design, the shoulder joint has plenty of mobility as the arm can move in multiple planes. This allows for reaching in many directions. Unfortunately, this mobility can also make it easier for the shoulder to have injuries.  Often, the shoulder is injured by falling on an outstretched hand.

Injuries to the Bones of the Shoulder

  • Dislocation usually refers to an episode where the humeral head becomes dislodged from the socket (glenoid). This can occur when someone falls on an outstretched arm.
  • Subluxation of the shoulder describes an episode where the humeral head partially slides out of the socket but does not come out completely.
  • Fractures occur when external forces overload the bone.  Therefore, the result is cracks and breaks in the bone matrix.  Please read this article on Proximal Humerus Fractures. 

Injuries to the Soft Tissue of the Shoulder

  • Shoulder Impingement is a condition where the tendons get pinched between the bones of the shoulder. Usually, this occurs in the space between the humeral head and the acromion process. Pinching can occur with the rotator cuff tendons when the humeral head is moving upward due to increased laxity, weak stabilizing muscles, or bony abnormalities of the acromion process.
Anatomy of shoulder problems

Posterior Shoulder Pain

  • Rotator Cuff Tears are common injuries in the shoulder where the rotator cuff tendons have torn. This can occur from trauma or can slowly develop over time from chronic shoulder impingement.
  • Labral Tears describe tearing or fraying of the lip of cartilage that surrounds the glenoid cavity. This often occurs when the shoulder dislocates or has had multiple episodes of subluxation.
Shoulder ROM Exercises

JOI Rehab Shoulder ROM Exercises

If you have recently had a shoulder surgery please watch this helpful video: Dressing the Upper Body After an Injury or Surgery

To make an appointment for physical therapy for the shoulder, please call 904-858-7045.

JOI Fracture and Injury Care

JOI Physicians are currently offering ASAP fracture and injury care.  Therefore, this is a new option for patients who would like to avoid the emergency room if they have suffered a fracture or soft tissue injury.  Finally, to make an appointment by calling (904)JOI-2000.

Book An Appointment with a JOI Physician.

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Image of Book An Appointment with a JOI Physician Button  By: Chad Evans PT

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