Anterior Glenohumeral Instability Clinical Presentation

Updated: Sep 20, 2022
  • Author: Brett D Owens, MD; Chief Editor: Mohit N Gilotra, MD, MS, FAAOS, FAOA  more...
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Anterior dislocation of the glenohumeral joint occurs with the arm in a forward flexed, abducted, and externally rotated position. Children presenting with a dislocated shoulder may relate a couple of possible mechanisms; most commonly, the child falls on the outstretched hand, forcing the arm into abduction, levering the humeral head out of the glenoid cavity. In adults, mechanisms include contact sports, after a fall from a height, fights, and motor vehicle accidents. Patients can experience a range of injury and most commonly report traumatic subluxation without frank dislocation.

According to data from the National Collegiate Athletic Association (NCAA), sports commonly implicated include football, hockey, wrestling, and other contact events. [33]


Physical Examination

Physical examination begins with inspection of the shoulder, especially as it compares to the asymptomatic side. Any atrophy of the biceps, supraspinatus, infraspinatus, or deltoid must be noted. Injury to the axillary or suprascapular nerves may be caused by previous dislocation and can be perceived as asymmetry of associated muscles on exam. [8]  Gross deformity can also suggest a dislocation and its direction; however, depending on the clinical setting, a dislocation may have been reduced previously. Both shoulders should be palpated, with a focus on tenderness, deformity, and crepitus. Tenderness at the lateral shoulder is frequently reported with Hill-Sachs lesion secondary to dislocation.

Passive and active range of motion (ROM) should then be assessed, including the following:

  • Forward flexion
  • Abduction
  • External rotation in adduction and 90º of abduction
  • Internal rotation behind the back and in 90º of abduction

Patients with a recent traumatic dislocation event often will have decreased ROM secondary to muscle guarding, inflammation, or pain, whereas  patients with chronic or atraumatic instability may demonstrate normal ROM or even hypermobility.

It is important to differentiate laxity from instability. Laxity in the shoulder is defined as the ability of the humeral head to be passively translated on the glenoid fossa. Patients presenting with shoulder instability frequently have generalized ligamentous laxity. The Beighton Hypermobility Score is a useful adjunct diagnostic tool. [34] In this tool, one point is given for each of the following:

  • Demonstrated hypermobility of the small-finger metacarpophalangeal (MCP) joint past 90º
  • Ability to connect the thumb and the volar forearm
  • Hyperextension at the elbow past 10º
  • Hyperextension at the knee past 10º
  • Ability to place both hands flat on the ground with knees extended

Because the first four are assessed bilaterally, the highest possible score is 9. Generalized laxity is defined as a score of 4 or higher. [34]  

Multiple examination tests have been described to assess shoulder-specific laxity, including the following [8] :

  • Anterior and posterior drawer tests
  • Load and shift test
  • Sulcus test (sulcus sign)
  • Gagey hyperabduction test 

The anterior drawer test is performed with the patient supine while the examiner holds the upper arm in 80-120º of abduction, 0-20º of forward flexion, and 0-30º of external rotation; in this position, the examiner then provides an anterior-directed force. [35]  The posterior drawer test uses a similar position but the examiner frames the patient’s shoulder with the thumb placed anteriorly and the fingers placed posteriorly while applying a posterior-directed force through the humeral head.

The load and shift test can be performed with the patient either seated or supine as the arm is held in slight abduction, 20º of forward flexion, and neutral rotation; while applying an axial load to the humeral head, the examiner simultaneously attempts to translate the humeral head anteriorly and posteriorly. [8]  Performing the load and shift test with the patient supine may help stabilize the scapula while allowing the patient to remain relaxed. The Gerber and Ganz classification grades translation from grade I (translation of the head to the glenoid rim) to grade III (translation over the glenoid rim without spontaneous reduction) for the anterior and posterior drawer tests and the load and shift test.

The sulcus test (sulcus sign) is performed on a seated patient with the arm adducted at the side in both neutral and external rotation; the test is positive if an inferior force results in inferior translation of the humeral head and a resulting space or sulcus between the acromion and the proximal humeral head.

The Gagey hyperabduction test is performed on a seated patient; the examiner uses one hand to stabilize the scapula and provide an inferior-directed force and the other hand to abduct the affected arm until the scapula is felt to begin rotation. [36]  A positive test is abduction to over 105º before scapular rotation.

As part of a full physical examination, shoulder strength should also be assessed, with a specific focus placed on each of the rotator cuff muscles in isolation. [8]  Briefly, the supraspinatus is evaluated with supraspinatus isolation (the Jobe test). The infraspinatus is evaluated with resisted external rotation with the elbow at the patient’s side. The teres minor is evaluated with the Hornblower test. Finally, the subscapularis can be evaluated with either the liftoff test, with the patient’s hand starting on the lumbar spine, or the belly-press test.

Impingement signs must also be evaluated because as many as 10% of patients experience impingement after dislocation. It is important to evaluate for the Hawkins sign and perform the Neer impingement test.

Provocative examination maneuvers can also assist the clinician in diagnosing and assessing anterior shoulder instability. The key finding in anterior glenohumeral instability is a positive apprehension test. The arm is placed in abduction, extension, and external rotation while being stressed in anterior translation. If the patient becomes apprehensive and reports pain, this is considered a positive finding. It is important to note that pain alone does not constitute a positive apprehension test: The patient must report apprehension.

The relocation test involves placing the shoulder in the position of apprehension and applying a posterior-directed force to the humeral head. The result is considered positive if this relieves the patient's apprehension.

The anterior release (surprise) test is also sensitive and specific for clinically diagnosing anterior shoulder instability. This test can be thought of as the last step of the apprehension test, in which the posterior-directed force is removed, and the patient once again reports apprehension or the feeling of impending dislocation. [37, 38]