Anatomy of the Shoulder


Pain and stiffness in the shoulder region can come from a variety of causes, ranging from physical injury or overuse to radiating pain from the cervical region of the neck.  Arthritic shoulder pain and aching is a common complaint from former athletes of all types and those who have done a great deal of physical labor throughout their lives.

One of the most common injuries to the shoulder is the rotator cuff tear, which involves four small muscles that support and surround the shoulder joint in a "cuff like" fashion.  Stretching exercises are surprisingly effective for shoulder pain and stiffness and can help prevent a debilitating condition commonly known as "frozen shoulder" which prevents the individual from raising their arm above their head.

Muscle Anatomy of the shoulder joint: 

The Deltoid is the large triangular muscle of the shoulder that forms the visible rounded flesh of the outer part of your upper arm. The deltoid muscle forms a shape resembling an inverted triangle in people with highly defined musculature. It passes up and over your shoulder joint.

The deltoid muscle is made up of three portions: the Anterior (front) Deltoid, the Medial (middle) Deltoid, and the Posterior (rear) Deltoid.

The action of the deltoid muscle is to raise your arm upward. The anterior fibers raise your arm to the front. The medial fibers raise your arm straight out to the side, and the posterior fibers lift your arm to the rear.

The group of muscles responsible for stabilizing the shoulder joint is commonly called the rotator cuff. These are the shoulder muscles often injured in sports, for example, by throwing a baseball or serving a tennis ball. The rotator cuff consists of four small muscles: the Supraspinatus, Infraspinatus, Teres Minor, and Subscapularis muscles, sometimes called the SITS muscles.