Adhesive capsulitis (AC), often referred to as Frozen Shoulder, occurs when the strong connective tissue surrounding the shoulder joint (called the shoulder joint capsule) become thick, stiff, and inflamed. Frozen shoulder is characterized by initially painful and later progressively restricted shoulder range of motion with spontaneous complete or nearly-complete recovery taking up to two to three years.

​

Frozen shoulder is complex and multifactorial with both genetic and environmental factors playing an important role.

 

1. Primary - Onset is generally idiopathic (it comes on for no attributable reason)
    

2. Secondary - Results from a known cause; predisposing factors where there may be altered movement patterns to protect the painful structures, which will in turn change the motor control of the shoulder, reducing the range of motion, and gradually stiffens up the joint.

​

Three subcategories of secondary frozen shoulder include:

1. Systemic (diabetes mellitus and other metabolic conditions);

2. Extrinsic factors (cardiopulmonary disease, cervical disc, stroke, humerus fractures, Parkinson’s disease)

3. Intrinsic factors (rotator cuff pathologies, biceps tendinopathy, calcific tendinopathy, AC joint arthritis).
    

Approximately 70% of individuals who present with a frozen shoulder, are females and individuals 35-65 years old. If an individual has had frozen shoulder (5-34% chance of having it in the contralateral shoulder at some point as well).