The hand behind the back test, also called the internal rotation lag sign or the lift-off test, is a diagnostic physical examination maneuver used to evaluate shoulder problems, particularly rotator cuff disorders. It assesses the range of internal rotation motion in the glenohumeral joint of the shoulder.
How the Test is Performed
The test is carried out as follows:
- The patient is asked to place the hand of the affected arm behind their back, as high up as possible, with the palm facing outwards.
- The examining physician then attempts to further lift the hand upwards, beyond the point reached by the patient’s own effort.
- The range of passive internal rotation is measured to compare with the unaffected side.
- The test can be done in both standing and supine positions.
- Some versions also assess the ability to maintain the elevated hand position against resistance.
What a Positive Test Signifies
- If the patient is unable to reach up the back due to pain and stiffness, it indicates a restriction in active internal rotation.
- When the examiner is unable to lift the hand further, it signifies limited passive mobility in the same movement.
- A lag sign or drop of the hand when resistance is applied suggests weakness of the internal rotators due to injury.
- Generally, a disparity of more than 10° between the two shoulders is considered abnormal and a positive finding.
- The test is positive in disorders affecting the shoulder joint’s inner mechanics like internal impingement, capsulitis, osteoarthritis as well as rotator cuff tears and tendinopathy.
- Loss of both active and passive range of motion points towards a capsular pattern of restriction or adhesive capsulitis.
- Normal active but limited passive motion is typical of shoulder osteoarthritis.
- Pain and weakness on resistance indicates rotator cuff pathology like supraspinatus tears, tendinitis or bursitis.
- The location of the pain can also help distinguish between different shoulder problems.
Advantages of the Test
- Quick, easy and inexpensive to perform during routine physical exams.
- Assesses both active and passive shoulder internal rotation.
- Provides direct comparison to the opposite side within the same patient.
- Does not require extensive equipment – just exam gloves and a goniometer.
- Well-tolerated by most patients with minimal discomfort.
- Allows specific diagnosis and aids in guiding appropriate treatment.
- Screening tool for general shoulder problems in office practice.
- Distinguishing co-existing shoulder pathologies like cuff tears with capsulitis.
- Determining the location and extent of internal impingement.
- Evaluating recovery progress and outcomes after rotator cuff repairs or stabilization surgery.
- Monitoring shoulder mobility in overhead athletes like swimmers and throwers.
- Results depend on the patient’s cooperation and effort level.
- The interpretation can be subjective and vary between examiners.
- Not reliable in obese patients or those with physical disabilities.
- Assesses only the sagittal plane internal rotation.
- Does not evaluate muscular strength or stability of the shoulder.
- Cannot identify the exact location or size of rotator cuff tears.
- Not sensitive for injuries in overhead athletes with acquired laxity.
- The hand behind back test provides the most useful information when combined with a complete history and clinical examination including inspection, palpation and other range of motion assessments.
- Additional tests for suspected rotator cuff disease include the drop arm test, empty can test and external rotation lag sign.
- Strength testing, impingement signs and instability maneuvers provide supplementary diagnostic information.
- Imaging like MRI arthrogram is needed to pinpoint the lesions and guide interventional treatment.
The hand behind back shoulder test is a simple, non-invasive screening tool to evaluate glenohumeral mobility and identify various shoulder pathologies. It delivers valuable clues for making an accurate diagnosis when used together with a comprehensive clinical workup. Though examiner-dependent and not able to characterize injuries in isolation, it remains a convenient bedside maneuver for assessing internal rotation limitations indicative of common shoulder problems.