What is frozen shoulder?

Frozen shoulder, also called adhesive capsulitis, is a painful condition in which the movement of the shoulder becomes limited.

Frozen shoulder occurs when the strong connective tissue surrounding the shoulder joint (called the shoulder joint capsule) become thick, stiff, and inflamed. (The joint capsule contains the ligaments that attach the top of the upper arm bone [humeral head] to the shoulder socket [glenoid], firmly holding the joint in place. This is more commonly known as the ‘ball and socket’ joint.)

The condition is called ‘frozen’ shoulder because the more pain that is felt, the less likely the shoulder will be used. Lack of use causes the shoulder capsule to thicken and becomes tight, making the shoulder even more difficult to move -- it’s ‘frozen’ in its position.

Who is at risk for developing frozen shoulder?

Age: Adults, most commonly between 40 and 60 years old.

Gender: More common in women than men.

Recent shoulder injury: Any shoulder injury or surgery that results in the need to keep the shoulder from moving (ie, by using a shoulder brace, sling, shoulder wrap, etc) Examples include a rotator cuff tear; and fractures of the shoulder blade, collarbone, or upper arm.

Diabetes: Between 10% and 20 % of individuals with diabetes mellitus develop frozen shoulder.

Other health diseases and conditions: stroke, hypothyroidism (underactive thyroid gland), hyperthyroidism (overactive thyroid gland), Parkinson’s disease, heart disease.

Stroke is a risk factor for frozen shoulder because movement of an arm and shoulder may be limited. Why other diseases and conditions increase the risk of developing a frozen shoulder is not clearly.

What are the signs and symptoms of frozen shoulder?

Symptoms of frozen shoulder are divided into three stages:

The ‘freezing’ stage: In this stage, the shoulder becomes stiff and is painful to move. The pain slowly increases. It may worsen at night. Inability to move the shoulder increases. This stage lasts 6 weeks to 9 months.

The ‘frozen’ stage: In this stage, pain may lessen, but the shoulder remains stiff. This makes it more difficult to complete daily tasks and activities. This stage lasts 2 to 6 months.

The ‘thawing’ (recovery) stage: In this stage, pain lessens, and ability to move the shoulder slowly improves. Full or near full recovery occurs as normal strength and motion return. The stage lasts 6 months to 2 years.