Stiff Shoulder

Stiff shoulder (adhesive capsulitis) is stiffness, pain, and limited range of movement in your shoulder. It may happen after an injury or overuse or from a disease such as diabetes or a stroke. The tissues around the joint stiffen, scar tissue forms, and shoulder movements become difficult and painful. The condition usually comes on slowly, then goes away slowly over the course of a year or more.
The shoulder has a spheroidal joint (ball – and – socket joint), in which the round part of one bone fits into the concavity of another. The proximal humerus (round head of the upper arm bone) fits into socket of the scapula (shoulder blade). Stiff shoulder is thought to cause the formation of scar tissue in the shoulder, which makes the shoulder joint’s capsule (not to be confused with the rotator cuff) thicken and tighten, leaving less room for movement. Therefore, movement may be stiff and even painful.
Causes
Stiff shoulder can develop when you stop using the joint normally because of pain, injury, or a chronic health condition, such as diabetes or a stroke. Any shoulder problem can lead to stiff shoulder if you do not work to keep full range of motion.
Stiff shoulder occurs:
After surgery or injury.
Most often in people 40 to 70 years old.
More often in women (especially in postmenopausal women) than in men.
Most often in people with chronic diseases.