Frozen Shoulder ( technical name : Adhesive capsulitis ) is a condition which causes severe pain and restricted movement of the shoulder joint. The pain is caused by abnormalities and hardening of the collagen in the tissues of the shoulder capsule joint.

The prevalence is estimated at 2% to 5% of the general population - i.e. many millions worldwide.

The cause is generally unknown, as is the underlying pathophysiology which leads to the joint degradation.

The condition can sometimes be partially relieved with NSAIDs, and usually self-resolves, but this can take many months, sometimes even years.

Microscopic analysis of tissue samples have found some similarities with the damage caused in Dupuytren's contractureplugin-autotooltip__plain plugin-autotooltip_bigDupuytren's contracture

"Dupuytren's contracture is a condition in which one or more fingers become permanently bent in a flexed position. It usually begins as small, hard nodules just under the skin of the palm, then worsens over time until the fingers can no longer be straightened. While typically not painful, some aching or itching may be present. The ring finger followed by the little and middle fingers are most commonly affected.The condition can interfere with preparing food, writing, an…, which also has an unknown cause. (Ref. Eur J Med Res,12: 585-590)

Note that it typically affects the 'non dominant' arm, also for unknown reasons.

Further info American Family Physician 99(5):297-300.