Etiology — what causes it

Inflammatory and fibrotic process within the glenohumeral joint capsule, causing capsular contracture. Idiopathic in many cases; secondary forms associated with diabetes mellitus (significantly increased risk), thyroid disease, prolonged immobilization, post-trauma, and after shoulder surgery.

Epidemiology — who gets it

Prevalence 2–5% in the general population; 10–30% in adults with diabetes. Peak age 40–60. Slight female predominance. Approximately 20–30% develop bilateral involvement (often sequential).

Clinical signs

Hallmark — restricted active AND passive range in a capsular pattern (external rotation most limited, then abduction, then internal rotation). Pain at end range. No drop sign, no significant weakness once pain is accounted for.

Symptoms

Insidious onset of shoulder pain often unrelated to a clear injury. Progressive loss of range — first noticed reaching behind back or overhead. Night pain prominent in the freezing phase. Phases: freezing (painful, 2–9 months) → frozen (stiff, less painful, 4–12 months) → thawing (improving range, 5–24 months).

Best evidence for chiropractic treatment

Page et al. (Cochrane 2014) and the JOSPT shoulder pain CPG support phase-based care: pain management in freezing (low-load mobilization, education, and sometimes intra-articular corticosteroid injection), and progressive mobilization and stretching in frozen and thawing phases. Hydrodilatation has evidence for shortening the freezing phase. Surgery (manipulation under anesthesia, arthroscopic capsular release) is reserved for refractory cases.

Subtypes

  • Primary (idiopathic). No clear trigger. Follows classic three-phase course.
  • Secondary (diabetes-associated, post-immobilization, post-surgical). Often more severe and slower to resolve, especially in diabetes.

When to seek emergency care

Some symptoms need urgent medical attention — not a chiropractic visit. Call 911 or go to the nearest emergency department for: progressive limb weakness, loss of bowel or bladder control, saddle anesthesia (numbness in the groin/inner thighs), severe unrelenting pain unrelieved by position, signs of fracture after significant trauma, chest pain, stroke-like symptoms (face drooping, arm weakness, speech changes), or any rapidly worsening or unusual symptom.

Bottom line

Frozen shoulder is self-limiting but slow — 12 to 18 months is typical. Phase-based care and education shorten the timeline and reduce pain along the way.