Focused examination of the rotator cuff including individual muscle testing, lag signs, and differentiation of partial from full-thickness tears.
The rotator cuff examination tests each of the four muscles individually. Examiners expect you to know the specific tests for supraspinatus, infraspinatus, teres minor, and subscapularis. Lag signs indicate complete tears, while weakness with pain may indicate partial tears or tendinopathy.
High-Yield Exam Summary
Rotator Cuff Muscles (SITS):
| Muscle | Origin | Insertion | Innervation | Action |
|---|---|---|---|---|
| Supraspinatus | Supraspinous fossa | Greater tuberosity (superior) | Suprascapular (C5,6) | Abduction initiation |
| Infraspinatus | Infraspinous fossa | Greater tuberosity (middle) | Suprascapular (C5,6) | External rotation |
| Teres Minor | Lateral scapula | Greater tuberosity (inferior) | Axillary (C5,6) | External rotation |
| Subscapularis | Subscapular fossa | Lesser tuberosity | Subscapular (C5,6) | Internal rotation |
Tear Patterns:
Supraspinatus integrity and strength
Weakness and/or pain compared to opposite side
Supraspinatus pathology (tear or tendinopathy)
Ability to detect true positives
Ability to exclude false positives
Supraspinatus integrity (alternative to Jobe's)
Weakness and/or pain
Supraspinatus pathology (may be more comfortable than empty can)
Ability to detect true positives
Ability to exclude false positives
Complete supraspinatus tear
Arm drops suddenly (cannot control descent)
Complete supraspinatus tear (unable to control eccentric contraction)
Ability to detect true positives
Ability to exclude false positives
Infraspinatus and teres minor strength
Weakness compared to opposite side
Infraspinatus tear or pathology
Ability to detect true positives
Ability to exclude false positives
Complete infraspinatus tear
Arm springs back into internal rotation (positive lag)
Complete infraspinatus tear (cannot maintain external rotation)
Ability to detect true positives
Ability to exclude false positives
Teres minor function (and posterior cuff)
Inability to externally rotate or maintain position
Teres minor and/or infraspinatus tear
Ability to detect true positives
Ability to exclude false positives
Subscapularis integrity
Inability to lift hand away from back
Subscapularis tear
Ability to detect true positives
Ability to exclude false positives
Complete subscapularis tear
Arm falls back to rest on back (positive lag)
Complete subscapularis tear
Ability to detect true positives
Ability to exclude false positives
Upper subscapularis integrity
Weakness (cannot resist external rotation force)
Upper subscapularis tear
Ability to detect true positives
Ability to exclude false positives
Subscapularis function
Elbow falls back behind trunk plane (uses shoulder extension instead)
Subscapularis weakness or tear
Ability to detect true positives
Ability to exclude false positives
Palpable rotator cuff defect
Palpable gap or defect in the cuff (soft tissue void)
Full-thickness rotator cuff tear
Ability to detect true positives
Ability to exclude false positives
Pain with Weakness:
Weakness without Pain:
Massive Rotator Cuff Tear Signs:
Lag Signs = Complete Tears:
Lag signs have HIGH SPECIFICITY - if positive, the tear is almost certainly complete.
"58-year-old woman with 6-month history of shoulder pain and weakness lifting arm."
| pattern | tests | clinicalFeatures | atrophy |
|---|---|---|---|
| Isolated Supraspinatus | Jobe's weak/painful, Drop arm + | Most common pattern | Supraspinatus fossa |
| Supraspinatus + Infraspinatus | Above + ER lag sign + | Posterosuperior tear | Both fossae |
| Massive Tear (3 tendons) | Multiple lag signs + | Pseudoparalysis | Generalized |
| Subscapularis Tear | Lift-off -, IR lag + | Less common, often traumatic | Anterior (hard to see) |
High-Yield Exam Summary