🥶 Frozen Shoulder Three-Phase Progression Simulator

Normal Shoulder Capsule and Full Range of Motion

A healthy joint capsule stays thin, elastic, and pain-free.

• 180°: Normal forward flexion (arm raised overhead)
• 90°: External rotation (arm held at side)
• ~15 mL: Capsule volume (loose synovial pouch)
• 2–5%: Lifetime incidence (of general population)

Capsule anatomy

Thin fibrous capsule surrounds the glenohumeral joint loosely.

Synovial lining

Synovium secretes fluid that lubricates smooth joint movement.

Risk factors

Diabetes and prolonged immobilization raise future risk sharply.

Women aged 40 to 60 face the highest risk.

Freezing Phase — Inflammation Ignites Progressive Motion Loss

Capsule inflammation triggers rising pain and shrinking range.

• 6–12 wk: Typical duration (months 1–3)
• 0 → 8: Pain trajectory (sharp early rise)
• ~50%: ROM lost by month 3 (of normal range)
• Present: Synovitis (drives early symptoms)

Synovial inflammation

Inflamed synovium thickens and produces excess joint fluid.

Capsular contracture begins

Collagen fibers start tightening around the joint capsule.

Pain-guarded movement

Patients guard the shoulder, worsening stiffness through disuse.

Night pain often disrupts sleep during this phase.

Frozen Phase — Fibrosis Locks the Joint in Place

Pain plateaus while dense fibrous tissue restricts motion severely.

• 4–6 mo: Typical duration (months 4–9)
• 40–50%: Range of motion (of normal capacity)
• Myofibroblasts: Fibrosis driver (thicken the capsule)
• Capsule folds: Adhesions (fuse together)

Capsular fibrosis

Dense collagen bands replace the once-elastic capsule tissue.

Axillary fold adhesion

Redundant capsule folds stick together, blocking rotation fully.

Pain stabilizes

Constant ache replaces sharp pain, motion stays severely limited.

Everyday tasks like reaching a seatbelt grow difficult.

Thawing Phase — Capsule Remodels and Motion Slowly Returns

Fibrous tissue gradually remodels, restoring flexibility and comfort.

• 6–9 mo: Typical duration (months 10–18)
• 4 → 1: Pain trajectory (steadily declining)
• +30–40%: ROM regained (over the phase)
• High impact: Physical therapy (accelerates recovery)

Collagen remodeling

Disorganized collagen reorganizes into a more elastic structure.

Progressive stretching

Guided stretching exercises gradually regain lost joint mobility.

Adherence matters

Higher treatment adherence speeds capsule loosening noticeably.

Recovery pace varies widely between individual patients.

Recovery — Near-Full Range of Motion Restored

Months of remodeling culminate in near-normal shoulder function.

• 90–100%: Final range of motion (of original range)
• 12–24 mo: Total timeline (average full course)
• <10%: Recurrence rate (in same shoulder)
• ~14%: Opposite shoulder risk (develops later)

Functional restoration

Most patients regain nearly all lost shoulder function.

Residual stiffness

A small minority retain mild permanent motion limits.

Long-term outlook

Overall prognosis stays favorable without surgical intervention needed.

Early treatment adherence shapes the ultimate recovery quality.