Glenohumeral Instability

Upper Limb

Overview

Glenohumeral instability is a condition characterized by excessive translation of the humeral head within the glenoid fossa, resulting from compromised dynamic or static stabilizers. This can manifest as anterior, posterior, inferior, or multidirectional patterns, with varying degrees of severity from microinstability to frank dislocation. Patients typically present with apprehension, pain, and functional limitations in specific arm positions.

Pathophysiology

The glenohumeral joint relies on a complex balance of static stabilizers (labrum, articular cartilage, joint capsule, and ligaments) and dynamic stabilizers (rotator cuff muscles and scapular stabilizers). Instability develops through traumatic injury (Bankart lesions, HAGL lesions, Hill-Sachs defects), repetitive microtrauma, inherent ligamentous laxity, or neuromuscular dysfunction. Compromised proprioception, altered scapulohumeral rhythm, and weakness in rotator cuff or scapular stabilizers perpetuate the unstable pattern. Chronic instability leads to degenerative changes, further articular surface damage, and secondary impingement.

Typical Presentation

Site

Anterior glenohumeral joint region; pain may radiate to lateral shoulder and upper arm; posterior shoulder pain if posterior instability

Quality

Sharp, catching sensation; sense of shoulder 'slipping' or 'dead arm' phenomenon; aching or dull discomfort with functional activities

Intensity

Variable, typically mild to moderate at rest, severe with provocative positions or functional demands; intensity increases with fatigue

Aggravating

Abduction with external rotation (throwing position, overhead activities); sudden arm movements; certain sleeping positions; fatigue during repetitive activities; specific arm positions (apprehension position); overhead sports

Relieving

Rest and immobilization; internal rotation positioning; anti-inflammatory modalities; controlled movement patterns; scapular stabilization

Associated

Apprehension and fear of movement; loss of proprioception; scapular dyskinesis; reduced rotator cuff strength; clicking or clunking sensations; difficulty with overhead activities; functional weakness; anterior shoulder capsule tightness; posterior capsule tightness (posterior instability)

Orthopaedic Tests

Test descriptions are written with AI assistance from standard clinical texts. Where a test lists Sources, its description has been checked against them; those sources are independent and do not endorse OsteoKit. Accuracy figures and grades (A–D) appear only when checked against the published study; tests without one are marked “No accuracy study”.

Further reading: full test procedures are described in standard clinical examination texts, e.g. Magee & Manske, Orthopedic Physical Assessment (7th ed.), and Cook & Hegedus, Orthopedic Physical Examination Tests: An Evidence-Based Approach (2nd ed.).

Grade A+
A+ABCDNear-definitive: a result is close to conclusive on its own (likelihood ratio ≥20 or ≤0.05)
best for ruling IN (confirmation).

Release (Surprise) Test

Procedure

Straight after the relocation test, with the backwards pressure applied and the shoulder in abduction and external rotation, suddenly release the pressure.

Positive Finding

Sudden return of apprehension, or the patient guards.

Sensitivity / Specificity

64%/99%

Reference: Lo IK et al., Am J Sports Med 2004; PMID 14977651

Interpretation

The most informative of the apprehension group for anterior instability. A positive result supports anterior instability. (The jerk test is a separate test for posterior instability; the previous interpretation of this test was incorrect.) Lo (2004) found the surprise (anterior release) test the single most accurate of the three instability tests (64% sensitivity / 99% specificity); apprehension and relocation alone were less accurate.

Sources

Grade A
A+ABCDStrong clinical value: substantially changes the diagnosis (LR ≥10 or ≤0.1)
best for ruling IN (confirmation).

Anterior Apprehension Test

Procedure

Patient supine, shoulder abducted to 90° and elbow bent to 90°. Slowly externally rotate the shoulder.

Positive Finding

The patient shows or reports apprehension (a feeling the shoulder will come out). Pain alone is less meaningful.

Sensitivity / Specificity

72% (46 with traumatic anterior instability)/96% (317 with other shoulder problems)

Reference: Farber AJ, Castillo R, Clough M, Bahk M, McFarland EG. Clinical assessment of three common tests for traumatic anterior shoulder instability. J Bone Joint Surg Am. 2006;88(7):1467-74.

Interpretation

Apprehension supports anterior instability. Use it with the relocation and release (surprise) tests, which add more information together than alone. From 363 patients examined before shoulder arthroscopy (Farber 2006): 46 had traumatic anterior instability and 317 had other shoulder problems. Counting apprehension (not pain) as a positive result, the test was positive in 72% of those with instability and negative in 96% of those without, so a positive test strongly supports instability. Using pain as the positive sign made the test less accurate.

Sources

Grade A
A+ABCDStrong clinical value: substantially changes the diagnosis (LR ≥10 or ≤0.1)
best for ruling IN (confirmation).

Relocation Test (Jobe Relocation Test)

Procedure

Straight after a positive apprehension test, in the same position, apply a backwards pressure on the front of the humeral head and continue external rotation.

Positive Finding

The apprehension eases with the backwards pressure, allowing more external rotation.

Sensitivity / Specificity

81% (46 with traumatic anterior instability)/92% (317 with other shoulder problems)

Reference: Farber AJ, Castillo R, Clough M, Bahk M, McFarland EG. Clinical assessment of three common tests for traumatic anterior shoulder instability. J Bone Joint Surg Am. 2006;88(7):1467-74.

Interpretation

Relief of apprehension supports anterior instability. Follow with the release (surprise) test. From 363 patients examined before shoulder arthroscopy (Farber 2006): 46 had traumatic anterior instability and 317 had other shoulder problems. Counting relief of apprehension as a positive result, the relocation test was positive in 81% of those with instability and negative in 92% of those without. Using relief of pain instead made it less accurate.

Sources

No accuracy study

Anterior Drawer Test

Procedure

Patient supine, shoulder abducted to about 80–120°, forward flexed and slightly externally rotated. Stabilise the scapula with one hand and draw the humeral head forwards with the other, comparing sides.

Positive Finding

More forward movement than on the other side, sometimes with a click or apprehension.

Interpretation

Shows anterior laxity. Laxity is common in people without symptoms and is not the same as instability; interpret it with the history and apprehension tests. In the same study as the apprehension figures (Farber 2006; 363 patients), the anterior drawer could be done in 87% of patients. When a positive test meant reproducing the patient's feeling of instability, it was positive in 53% of those with instability and negative in 85% of those without. Those figures are for that symptom-based definition, not for extra movement alone, so no figure is shown against this entry.

Sources

  • Educational sitePhysiopedia. Anterior Drawer Test of the Shoulder.
  • RelatedFarber AJ, Castillo R, Clough M, Bahk M, McFarland EG. Clinical assessment of three common tests for traumatic anterior shoulder instability. J Bone Joint Surg Am. 2006;88(7):1467-74.
No accuracy study

Sulcus Sign (Inferior Instability)

Procedure

Patient seated, arm relaxed at the side. Pull the arm gently downwards at the elbow and look for a dip below the acromion. Repeat with the shoulder externally rotated.

Positive Finding

A visible gap below the acromion, compared with the other side; a gap that persists in external rotation is more significant.

Interpretation

Shows inferior laxity. A large sulcus, especially on both sides, suggests generalised laxity or multidirectional instability, usually managed with rehabilitation of the rotator cuff and scapular muscles first.

Sources

Not a diagnostic test

Passive External Rotation at 0° Abduction

Procedure

Patient supine or seated, arm at the side, elbow bent to 90°. Passively rotate the forearm outwards to the end of range and compare with the other side.

Positive Finding

Clearly more external rotation than on the other side, or apprehension in this position.

Interpretation

Excess external rotation at the side suggests anterior capsular laxity or generalised hypermobility. It is a range check, not a diagnostic test; the crank test is a separate labral test.

Sources

⚠ Red Flags

  • •Acute glenohumeral dislocation requiring emergency reduction
  • •Neurovascular compromise (axillary nerve injury, vascular injury)
  • •Significant bony defects (Hill-Sachs lesion >25%, glenoid bone loss >20%) requiring surgical intervention
  • •Fracture-dislocation or associated fractures
  • •Recurrent dislocation episodes (>2 dislocations, especially in contact athletes)
  • •Failed conservative management with persistent instability despite 3+ months of structured therapy
  • •Signs of associated labral pathology with mechanical locking or catching
  • •Systemically hypermobile Ehlers-Danlos syndrome or Marfan syndrome requiring specialist assessment

⚡ Yellow Flags

  • •High-level athlete with instability affecting career/livelihood
  • •Fear-avoidance beliefs preventing engagement in rehabilitation
  • •Repeated injury pattern suggesting possible inadequate rehabilitation compliance
  • •Psychological distress related to injury and functional limitations
  • •Secondary gains associated with chronic shoulder dysfunction
  • •Perfectionist or high-performance athlete mentality affecting recovery pacing
  • •Limited coping mechanisms for managing shoulder function restrictions
  • •Anxiety regarding re-dislocation during rehabilitation progression

Osteopathic Techniques

Rehab is exercise-led: rotator cuff and posterior deltoid strengthening may reduce recurrence and pain in posterior instability, based on low-level studies. No trials of manual techniques in shoulder instability were found.

Region

Posterior shoulder (horizontal abductors and external rotators)

Technique

Muscle energy, glenohumeral (posterior shoulder)No trials found

Rationale

Patient-powered stretch for posterior tightness, alongside cuff strengthening. No trials in instability.

How it's done, cautions & evidence

How it's done

Take the arm to the barrier in horizontal adduction or internal rotation. The patient gently pushes back (horizontal abduction or external rotation) against equal resistance at 10–20% effort for 5–10 seconds, then relaxes for 3–5 seconds, and the arm is taken to the new barrier. Repeat 3–5 times, then re-check range.

Cautions

Very safe, but not used with a fracture, a ruptured ligament, tendon or muscle, or a joint infection.

Evidence in Glenohumeral Instability

Searched 24 Oct 2026: no trials of glenohumeral MET in shoulder instability.

Region

Rotator cuff, deltoid and periscapular muscles

Technique

Soft tissue, shoulder and periscapular musclesNo trials found

Rationale

Eases tension in the rotator cuff and shoulder blade muscles. No trials in instability.

How it's done & evidence

How it's done

Hands-on kneading, stroking and sustained pressure to the muscles around the shoulder: the rotator cuff, deltoid and the muscles around the shoulder blade. In trials it was given alongside shoulder exercise.

Evidence in Glenohumeral Instability

Searched 24 Oct 2026: no trials of shoulder soft tissue technique in shoulder instability.

Region

Upper and mid thoracic spine

Technique

Articulation, thoracicNo trials found

Rationale

Gentle upper-back mobilisation. No trials in instability.

How it's done & evidence

How it's done

Rhythmic, low-velocity movement of restricted thoracic segments within their passive range, with no thrust. The patient is seated, side-lying or prone. For neck problems the upper thoracic segments (T1–T6) are the usual focus.

Evidence in Glenohumeral Instability

Searched 24 Oct 2026: no trials of thoracic mobilisation in shoulder instability.

Sources

Rehabilitation Exercises

Pendulum Circles

Range of MotionBeginner

Cross-Body Shoulder Stretch (Horizontal Adduction)

StretchingBeginner

Sleeper Stretch (Posterior Capsule)

StretchingBeginner

Scapular Retraction with Prone Walkout

PosturalIntermediate

Isometric External Rotation (Neutral Position)

StrengtheningBeginner

Prone Shoulder External Rotation with Band

StrengtheningIntermediate

Prone Horizontal Abduction at 90 Degrees

StrengtheningIntermediate

Lower Trapezius Activation (90/90 Position)

StrengtheningIntermediate

Quadruped Shoulder Taps

BalanceIntermediate

Prone Push-up with Scapular Emphasis

StrengtheningAdvanced

PNF D2 Flexion Pattern (Standing with Resistance Band)

BalanceAdvanced

Submaximal Rowing Machine (Controlled Ergometer)

CardiovascularIntermediate

Referral Criteria

  • •Acute dislocation or recurrent dislocations (>2 episodes) requiring orthopedic evaluation for imaging and surgical consideration
  • •Failure to progress after 8-12 weeks of structured conservative management
  • •Severe pain with significant functional limitations unresponsive to manual therapy and exercise
  • •Clinical suspicion of labral pathology (SLAP lesion, Bankart lesion) with positive imaging findings
  • •Significant bony defects or fracture-dislocation requiring surgical stabilization
  • •High-demand athletes seeking return to contact or overhead sports requiring specialist clearance
  • •Neurovascular compromise or axillary nerve injury
  • •Systemic connective tissue disorders (Ehlers-Danlos, Marfan syndrome) requiring multidisciplinary team approach
  • •Persistent instability despite optimal rehabilitation suggesting possible undiagnosed pathology
  • •Mental health concerns or significant psychological distress interfering with rehabilitation engagement