Rotator Cuff Tear vs Labral Tear vs Impingement: Shoulder Pain Differential
Special Tests · 8 min read · 2026-02-21
Introduction
Shoulder pain accounts for roughly 16% of all musculoskeletal complaints. Three conditions dominate the differential: rotator cuff tears, labral tears, and subacromial impingement. While imaging provides the definitive answer, clinical examination can accurately narrow the diagnosis before a single scan is ordered.
Subacromial Impingement
The rotator cuff tendons pass beneath the coracoacromial arch. Narrowing of this space — from bony spurs, bursal inflammation, or scapular dyskinesis — compresses the supraspinatus tendon.
Pain pattern: Anterolateral shoulder pain, worse with overhead activities. The painful arc occurs between 60–120° of abduction.
Key tests: Neer's sign (passive forward flexion with scapula stabilized), Hawkins-Kennedy (internal rotation at 90° flexion), Jobe's test may be painful but strong.
Distinguishing feature: Full strength is maintained. The patient has pain but no true weakness.
Rotator Cuff Tear
A partial or full-thickness tear of one or more rotator cuff tendons, most commonly supraspinatus.
Pain pattern: Deep aching in the deltoid region. Night pain is characteristic — patients cannot sleep on the affected side. History of a specific injury or progressive degeneration.
Key tests: Jobe's (empty can) test — pain AND weakness. Drop arm test positive in full-thickness tears. External rotation lag sign for infraspinatus tears. Hornblower's sign for teres minor.
Distinguishing feature: True weakness that cannot be explained by pain inhibition alone. In full tears, the patient literally cannot hold the arm in position.
Labral Tear (SLAP / Bankart)
Tears of the glenoid labrum, either superior (SLAP — Superior Labrum Anterior to Posterior) or inferior-anterior (Bankart, associated with dislocation).
Pain pattern: Deep, poorly localized shoulder pain. Mechanical symptoms — clicking, catching, or a sense of instability. Often in younger athletes with overhead sports.
Key tests: O'Brien's test (active compression), Speed's test, anterior apprehension and relocation test (Bankart). Crank test. The pain is typically reproduced with specific positions rather than ranges of motion.
Distinguishing feature: Mechanical symptoms (clicking, catching) and a history of instability or subluxation. The pain is positional, not arc-related.
Quick Comparison
Clinical Pearl
The "drop arm" test is highly specific for a full-thickness rotator cuff tear. If a patient cannot slowly lower their arm from 90° abduction without it dropping, you can be nearly certain of a complete tear — order the MRI for surgical planning, not diagnosis.
Summary
Pain with full strength = impingement. Pain with true weakness = rotator cuff tear. Clicking, catching, or instability in a young athlete = labral pathology. The history often tells you more than the examination.