Lateral Rotation Lag Sign | Full-Thickness Rotator Cuff Tear Assessment
The Lateral/External Rotation Lag Sign also known as Infraspinatus Spring Back Test assesses for pain or weakness of the supraspinatus, infraspinatus and teres minor muscle.
In a study by Miller et al. (2008), the Lag Sign had a sensitivity of 46% and a specificity of 94% for full-thickness tears of the supraspinatus and infraspinatus.
This means that this test is useful to confirm the presence of full-thickness tears with a positive likelihood ratio of 7.2, but has only a weak ability to rule out full-thickness tears.
To perform the test have your patient in standing position with his arms flexed to 90°. Then the examiner brings the shoulders into 90° of abduction in the scapular plane and laterally rotates the shoulders to end-range and asks the patient to hold it.
The test is positive if the patient cannot hold the position and the springs back anteriorly indicating that the infraspinatus and teres minor cannot hold the position due to pain or weakness
21 OF THE MOST USEFUL ORTHOPAEDIC TESTS IN CLINICAL PRACTICE
Other orthopedic tests to assess for full-thickness tears of the rotator cuff muscles of the shoulder are:
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