Shoulder Instability Tests:A Physiotherapist's Clinical Guide

Shoulder instability is not a single diagnosis. It is a family of presentations grouped by direction (anterior, posterior, inferior, or multidirectional), by mechanism (traumatic versus atraumatic), and by the structural lesion (capsular laxity, Bankart lesion, Hill-Sachs defect, SLAP tear, posterior labral lesion). The clinically important separation, often abbreviated as TUBS versus AMBRI, drives management: a traumatic, unidirectional, Bankart-lesion shoulder usually goes to surgery, while an atraumatic, multidirectional, bilateral, rehabilitation-responsive shoulder usually does not.

Direction-specific tests are how the bedside examination commits to a label. The apprehension-relocation-surprise sequence targets anterior instability. Kim's, jerk, and Porcellini target posterior labral lesions and posteroinferior instability. Sulcus sign and Gagey target inferior laxity. Load and shift assesses laxity in both anterior and posterior directions but does not identify the symptomatic direction on its own. Picking the right tests for the patient's presentation, and interpreting them together, is the skill the literature rewards.

A clear story of a traumatic dislocation, particularly with the arm in abduction and external rotation (the classic anterior dislocation mechanism), simplifies the picture. The patient describes a violent dislocation, often requiring reduction, and now reports apprehension whenever the arm approaches the cocking position. This is the textbook anterior-instability presentation and the apprehension-relocation cluster carries the strongest evidence here.

Atraumatic and multidirectional instability is harder. The patient describes recurrent subluxations or dislocations without a clear injury, often with bilateral symptoms and a history of generalized joint laxity. Pain may be the chief complaint rather than instability itself. Test in multiple directions, expect a positive sulcus, and look for hyperlaxity signs (Beighton score, hypermobility).

Posterior instability is the most commonly missed pattern. Patients describe deep posterior shoulder pain with the arm forward-flexed and internally rotated (pushing through a door, bench press, the follow-through of a throw). They rarely say 'my shoulder dislocates' because subluxation is silent. Push-up pain, bench-press pain, and a history of swimming or throwing should prompt posterior-specific testing (Kim's, jerk, Porcellini) even if anterior tests are negative.

The strongest evidence for diagnosing traumatic anterior instability at the bedside is the apprehension-relocation-surprise sequence. Each manoeuvre on its own has moderate accuracy; the three taken as a cluster, particularly when apprehension is the criterion rather than pain, gives one of the highest reported likelihood ratios in shoulder examination.

In this sectionApprehension test · Relocation test · Release / surprise test

Apprehension test

Position the patient supine or sitting with the shoulder abducted to 90 degrees. Slowly externally rotate toward end range while applying a gentle anteriorly directed force to the posterior humeral head. The test is positive when the patient becomes apprehensive or resists further motion because the shoulder feels as if it will dislocate. Pain alone is the weaker positive criterion; apprehension is the instability-specific finding (Lo 2004).

Move slowly. Forced external rotation in a hyperlax anterior shoulder can provoke dislocation, particularly in a patient with a recent first-time event. Full procedure and the Lo et al. cluster data here.

The load and shift is a laxity test, not a diagnostic test. Stabilize the scapula and clavicle, grasp the humeral head between the thumb (posteriorly) and fingers (anteriorly), centre the head in the glenoid, then translate it anteriorly and posteriorly. Compare the amount of translation, the end feel, and whether the manoeuvre reproduces the patient's familiar symptoms with the unaffected side.

Two important caveats. First, asymptomatic translation is common, particularly in athletic shoulders, so the magnitude alone is not diagnostic; side-to-side difference and reproduction of the patient's symptoms are what matter. Second, you must centre the humeral head before you shift it; an off-centre starting position is the most common cause of a false negative (Magee). Interpret the test as evidence for laxity in a particular direction, then combine with the cluster tests above and below to decide whether the laxity is symptomatic. Full procedure, end-feel grading, and study data here.

Inferior laxity is a hallmark of multidirectional instability and may be the most prominent finding in atraumatic, hyperlax patients. The two bedside tests are the sulcus sign and the Gagey hyperabduction test.

In this sectionSulcus sign · Gagey hyperabduction test

Posterior labral lesions and posteroinferior instability are the most commonly missed shoulder diagnoses in outpatient physio. Three bedside tests carry the strongest published accuracy.

In this sectionKim's test · Jerk test · Porcellini test

Jerk test

Sit the patient with the arm internally rotated and forward-flexed to 90 degrees. Apply an axial load proximally through the humerus and maintain it while horizontally adducting the arm across the body. A sudden jerk or clunk as the humeral head subluxes posteriorly is positive. A second jerk may be felt as the head reduces when the arm is returned to the start.

Kim 2005 reported the jerk test at 73 percent sensitivity and 98 percent specificity (likelihood ratio over 36), placing it among the highest specificity instability tests in the shoulder literature. A reproduced jerk that reproduces the patient's symptoms is a strong rule-in. Painful clicking without a clear jerk is less specific. Full procedure and study data here.

In this sectionA practical instability cluster · When to image and refer

Shoulder instability examination rewards cluster thinking far more than single tests. A practical bedside framework:

If you are a patient who suspects shoulder instability rather than a clinician, this section is the short version. The bedside tests above are designed for trained physiotherapists, but a few patterns are worth knowing before you book an appointment.

Signs that point to shoulder instability: a previous dislocation that needed reduction at A&E, a sense that the shoulder “slips” or feels apprehensive in certain positions (most often arm overhead, throwing position), shoulder giving way when reaching backward or above the head, or recurrent painful clicks deep in the back of the shoulder during bench press, push-ups, or sport. Some patients have generalised hypermobility and notice both shoulders are loose.

Things you should NOT do: avoid testing yourself with apprehension-style positions (arm out to the side, then rotated up toward your ear). A recently dislocated shoulder can re-dislocate in this position. Avoid heavy bench-press, overhead pressing, and contact sport until a physiotherapist or sports medicine doctor has assessed the joint.

When to see a clinician promptly: any shoulder that has dislocated within the last few weeks, especially if you are under 30 (recurrence rates are high in this group and early structured rehabilitation matters), if you cannot raise the arm above shoulder height, if there is numbness or weakness in the arm or hand after a dislocation, or if the shoulder repeatedly gives way during everyday activities.

The honest answer about “home tests”: there is no reliable self-test for shoulder instability. The Beighton score is a generalised laxity screen that suggests hypermobility but does not diagnose instability. The provocation tests above (apprehension, jerk, Kim's) need a trained examiner to perform safely. Use the symptom pattern to decide whether to book an appointment, and let the physiotherapist or doctor do the testing.

Real questions students and clinicians ask.

QWhat is the best test for shoulder instability?

ANo single test is best on its own. The strongest evidence is for the apprehension-relocation-surprise cluster in anterior instability (Lo et al. 2004; Speer et al. 1994), and for Kim's and jerk tests in posteroinferior labral lesions (Kim 2005). For multidirectional instability, the sulcus sign plus Gagey plus load and shift in multiple directions is the standard pattern. Use direction-specific clusters rather than a single 'best' test.

QWhat is the difference between the load and shift test and the apprehension test?

AThe load and shift assesses laxity (how much the humeral head can be translated), while the apprehension test assesses symptomatic anterior instability (whether the patient is afraid the shoulder will dislocate in the cocking position). A patient can be lax on load and shift without being unstable; the apprehension test is the symptom-driven counterpart that ties the laxity to a clinical problem.

QHow do I assess posterior shoulder instability?

ARun Kim's test and the jerk test, both of which load the posterior labrum directly. Look for sudden posterior pain or a jerk/clunk as the humeral head subluxes posteriorly. Add the Porcellini test for symptom modification with posterior stabilization. Posterior instability often presents as pain rather than overt instability, so the history (bench press, push-up, throwing follow-through) is as important as any single test.

QWhy does pain matter less than apprehension in the apprehension test?

AMany shoulder pathologies cause pain in the abducted, externally rotated position, including rotator cuff disease, internal impingement, and labral pathology. Apprehension (the patient bracing against further motion because the shoulder feels as if it will dislocate) is far more specific to true instability. Magee and Lo et al. both emphasize this distinction, and the strong likelihood ratios for the apprehension-relocation cluster rest on apprehension as the criterion, not pain.

QIs a positive sulcus sign always pathological?

ANo. A bilateral sulcus sign in an asymptomatic young adult is just laxity, common in athletic and hypermobile populations. Treat the sulcus sign as pathological only when it is symptomatic, asymmetric, or associated with a subluxation sensation. The same caveat applies to the load and shift test: asymptomatic translation is common and is not, on its own, a diagnosis.

QWhat does a positive apprehension test feel like?

AFrom the patient's perspective, the shoulder feels as if it is about to dislocate as the examiner reaches end-range external rotation. Most patients tense up, brace the shoulder, or actively resist the motion. Some describe a vivid sense of impending dislocation; others just say they don't trust the shoulder in that position. Pain alone, without that apprehension feeling, is the weaker positive criterion and is much less specific to instability.

QHow can I tell if my shoulder is unstable?

AThe most useful clue is the pattern: shoulder pops out (or feels close to popping out) in specific positions like arm overhead, throwing, or reaching backward; the shoulder “slips” with sudden movements; or there is a previous traumatic dislocation that needed reduction. Posterior instability often hides as deep posterior shoulder pain on bench press or push-ups without overt dislocation. A trained physiotherapist will run the apprehension, relocation, and direction-specific cluster tests for a formal assessment.

QDoes shoulder instability always need surgery?

ANo. Multidirectional instability and most atraumatic instability respond well to structured rehabilitation focused on rotator cuff and scapular stabiliser training. Surgery is most often considered for traumatic anterior dislocation in younger patients (recurrence rates are high), failed conservative rehab, or specific labral lesions (Bankart, posterior labral tear) where the structural lesion is clear on imaging and the patient wants to return to high-demand sport.

1. Lo IK, Nonweiler B, Woolfrey M, Litchfield R, Kirkley A (2004). An evaluation of the apprehension, relocation, and surprise tests for anterior shoulder instability. American Journal of Sports Medicine.
2. Speer KP, Hannafin JA, Altchek DW, Warren RF (1994). An evaluation of the shoulder relocation test. American Journal of Sports Medicine.
3. Kim SH, Park JS, Jeong WK, Shin SK (2005). The Kim test: a novel test for posteroinferior labral lesion of the shoulder, a comparison to the jerk test. American Journal of Sports Medicine.
4. Tzannes A, Paxinos A, Callanan M, Murrell GAC (2004). An assessment of the interexaminer reliability of tests for shoulder instability. Journal of Shoulder and Elbow Surgery.
5. Eshoj H, Ingwersen KG, Larsen CM, Kjaer BH, Juul-Kristensen B (2018). Intertester reliability of clinical shoulder instability and laxity tests in subjects with and without self-reported shoulder problems. BMJ Open.
6. Morey VM, Singh H, Paladini P, Merolla G, Phadke V, Porcellini G (2016). The Porcellini test: a novel test for accurate diagnosis of posterior labral tears of the shoulder: comparative analysis with the established tests. Musculoskeletal Surgery.
7. Magee DJ (2014). Orthopedic Physical Assessment, 6th edition. Saunders.

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