How do you tell rotator cuff related pain from a frozen shoulder?
Using passive external rotation, history and loading tests to separate rotator cuff related shoulder pain from frozen shoulder, with red flags to rule out first.
Subjective triage
- Rotator cuff related pain: lateral upper-arm pain with overhead or loaded tasks, often after a change in activity.
- Frozen shoulder: gradual, severe pain with progressive global stiffness, often in people aged 40 to 60.
- Frozen shoulder is more common in people with diabetes or thyroid conditions.
- Night pain and difficulty lying on the shoulder can occur in both.
- Ask about trauma, previous dislocation and neck symptoms to rule out other sources.
Differential dilemma: vs frozen shoulder
| Feature | Rotator cuff related shoulder pain vs frozen shoulder | Frozen shoulder |
|---|---|---|
| Passive external rotation | Largely preserved | Markedly restricted, often the most limited movement |
| Active vs passive range | Active may be painful or limited, passive close to full | Both active and passive equally restricted |
| Resisted testing | Pain on resisted movement or loading | Strength often relatively preserved within available range |
| Course | Linked to load changes, fluctuates | Painful then stiff phases over many months |
Red flags: recognise, screen, refer
Recognise
- Trauma with loss of active movement (possible acute cuff tear or dislocation)
- Hot, swollen joint or fever (possible infection)
- History of cancer, unexplained weight loss or a mass
- Neurological deficit in the arm
Screen
Check history of trauma, systemic symptoms and neurology, and consider referred pain from the neck, heart or abdomen.
Refer
Suspected infection or unreduced dislocation needs same-day assessment. Acute traumatic cuff tear needs prompt orthopaedic review. Suspected malignancy follows urgent pathways.
The clinical reasoning chain
- 1
History
Gradual onset of severe pain over three months, now unable to reach behind her back. Has type 2 diabetes.
- 2
Pattern
Global stiffness with a metabolic risk factor fits frozen shoulder more than cuff-related pain.
- 3
Objective finding
Passive external rotation restricted by more than half, normal X-ray if already taken, no red flags.
- 4
Diagnostic decision
Probable frozen shoulder: education on its natural course, pain-guided movement, and discussion of injection options with the team.
Structures to explore in 3D
In Physivo lessons, tap an anatomical term to focus the 3D model on it. These are the key structures for this presentation.
Glenohumeral joint capsule
Thickening and contraction of the capsule drives the stiffness in frozen shoulder.
Supraspinatus tendon
The cuff tendon most often linked to load-related lateral shoulder pain.
Rotator interval
Often involved early in frozen shoulder and linked to loss of external rotation.
Subacromial space
Where the cuff and bursa sit beneath the acromion during overhead movement.
Quick diagnostic check
Quick reference FAQ
What is the key test to differentiate frozen shoulder?
Loss of passive external rotation is the hallmark. If passive external rotation is largely preserved, frozen shoulder is less likely.
Is rest best for rotator cuff related shoulder pain?
Usually not. Exercise-based care with graded loading is the core treatment, with activity modification rather than complete rest.
How long does frozen shoulder last?
It often lasts many months and can take a year or more to resolve. Many people improve, but some have lasting restriction.