Execution
- 1Position the patient sitting or standing with the elbow flexed to 90°.
- 2Place the arm by the side or in approximately 20° abduction in the scapular plane.
- 3Passively externally rotate the shoulder to the maximum available range.
- 4Ask the patient to hold that externally rotated position while the examiner releases support.
- 5Observe whether the arm springs back into internal rotation and estimates the degree of lag.
Positive outcome
The test is positive if the patient cannot maintain the externally rotated position and the arm springs back toward internal rotation. Magee notes that this variant is used for supraspinatus and infraspinatus tears; more than about 40° of lag raises concern for teres minor involvement.
Studies
| Study | Reliability | Sn | Sp | LR+ | LR− |
|---|---|---|---|---|---|
| Hertel et al. (1996) | NA | NA | NA | NA | NA |
| Jain et al. (2017) | NA | 10 | 98 | 6.06 | NA |
| Miller et al. (2008) | NA | NA | NA | NA | NA |
CommentLag signs are better rule-in signs than screening tools because specificity is consistently higher than sensitivity. Hertel’s original work established the lag-sign concept, while later work shows that the 0° external rotation lag sign has high specificity but poor sensitivity. A negative lag does not exclude a full-thickness cuff tear, especially when pain inhibition, partial tearing, or compensation is present.
Moderate Clinical Value