Crank test: How to perform, interpret and document findings

Key takeaways

The crank test is an orthopedic special test for labral tears and SLAP lesions in the glenohumeral joint.

A positive result reproduces the patient’s familiar pain, a click, or a catching sensation under axial compression with rotation.

Reported sensitivity runs from 8.7% to 91% across studies. That spread tracks examiner count and cohort selection more than technique.

Several widely quoted accuracy figures are credited to the wrong paper, so check the citation before you rely on a number.

Structured examination templates in practice management software like Pabau keep special test findings readable across a full clinical team.

A missed labral tear costs the patient months. The crank test gives you a rapid, low-cost signal for glenohumeral labral pathology before you order imaging. Performed the same way every time, it narrows the differential. Performed loosely, it adds noise to the record.

This guide covers the procedure, the interpretation criteria, and what the accuracy literature actually says. It also corrects an attribution error that runs through much of the summary literature. Several accuracy figures quoted for the crank test belong to a different study than the one they are credited to.

It is written for physical therapists, orthopedic clinicians, and sports medicine practitioners assessing shoulder pain of suspected labral or SLAP origin. The last two sections cover documentation language and the workflow around it.

What is the crank test and who is it for?

The crank test is a clinical special test that detects tears of the glenoid labrum, including SLAP lesions and anterior or posterior labral tears. SLAP stands for superior labrum anterior to posterior.

Liu et al. first described the test in 1996, and it belongs to the axial compression-rotation family used in sports medicine and musculoskeletal orthopedic assessment.

The test loads the glenohumeral joint, the ball-and-socket articulation between the humeral head and the glenoid fossa of the scapula. The glenoid labrum is a fibrocartilaginous rim that deepens that socket and adds stability. It also anchors the long head of the biceps tendon at the superior aspect, which is what a SLAP lesion disrupts.

Compressive loading plus rotation provokes the labral tissue mechanically. That combination reproduces the catching or grinding a damaged labrum produces under load. The crank test is indicated in patients presenting with:

• Deep shoulder pain, often poorly localized
• Clicking, clunking, or a catching sensation with overhead activity
• A fall on an outstretched hand, or repetitive overhead loading in swimmers, throwers, and gymnasts
• Suspected glenohumeral instability without a frank dislocation history
• Shoulder pain that persists despite rotator cuff treatment

How to perform the crank test: Step-by-step

Procedural consistency decides whether the crank test helps or confuses. Two arm positions appear in the literature. The original Liu et al. protocol used 90 degrees of abduction, and several later studies used 160 degrees of elevation in the scapular plane. Both are valid, so note which one you used and findings stay comparable across assessors and follow-up visits.

Patient and examiner setup

Position the patient seated or standing, whichever gives you full access to the shoulder and arm. Elevate the arm to roughly 90 degrees of abduction in the scapular plane, about 30 degrees anterior to the coronal plane. For the modified version, elevate to 160 degrees instead. Flex the elbow to approximately 90 degrees.

Stand on the side being tested. One hand supports the elbow, holding the arm position and applying the axial load. The other hand sits proximal to the wrist and controls humeral rotation.

Applying the axial load and rotation

With the arm at the chosen elevation angle, apply firm axial compression along the shaft of the humerus toward the joint. Hold that compressive load throughout the maneuver.

While sustaining compression, rotate the humerus slowly through its internal and external rotation arc. Keep the sweep deliberate rather than rapid. Speed costs you the ability to feel subtle catching.

Watch for the patient’s familiar shoulder pain, an audible or palpable click, a clunk, or a reported catching sensation. Record the arc of rotation where any response appears, and whether it fell in the internal or external rotation phase.

How to interpret a positive crank test

The crank test is positive when it reproduces the patient’s pain, or when you detect a click, clunk, or catching sensation during the compression-rotation sequence. Not every shoulder click counts. The response has to be familiar to the patient as their presenting symptom. Incidental clicking without pain reproduction carries much less weight.

Interpretation by response pattern:

A single positive crank test suggests labral pathology rather than confirming it. Clinical reasoning has to take in the full history, the mechanism of injury, and the patient’s activity demands. Read the other shoulder special tests before you commit to an impression.

Diagnostic accuracy: Sensitivity, specificity and likelihood ratios

Reported accuracy for the crank test swings widely, and that spread matters more than any single figure you can quote.

The original Liu et al. study (PubMed PMID 8947391) used a cohort undergoing arthroscopy. It compared the crank test against the O’Brien active compression test and routine MRI.

The crank test reached 91% sensitivity and 93% specificity for labral tears. Later independent studies reported sensitivity between 8.7% and 46%, with specificity from 56% to 82.6%.

Two factors drive that difference. Liu’s cohort was pre-selected and read by a single experienced examiner, while later cohorts were broader and used multiple examiners. Arm position protocol and the mix of lesion types also differ from study to study.

Attribution is the second problem. The 46% sensitivity and 56% specificity figures that circulate under the name Parentis et al. come from Stetson and Templin’s 2002 cohort. Parentis and colleagues reported 8.7% sensitivity and 82.6% specificity for the crank test in their own 2006 series. Check which paper a number belongs to before you quote it in a report.

Set side by side, the published figures read less like one accuracy estimate and more like three different questions.

So where does that leave you at the bedside? The crank test performs best with an experienced examiner, a pre-selected population, and other tests read alongside it. A positive likelihood ratio near 1.7 to 2.0 raises the pre-test probability of labral pathology modestly. It does not rule the diagnosis in or out on its own.

Crank test vs. O’Brien test: Key differences

The O’Brien test is the alternative clinicians reach for most often when SLAP pathology is on the list. Both tests target superior labral tissue, and each loads it a different way. Which one you choose depends on the clinical question and on how well the patient tolerates the maneuver.

One caution on that accuracy row. The crank figures come from Liu’s 1996 series and the O’Brien figures come from Stetson and Templin’s 2002 series. They are two different cohorts, so the row is not a head-to-head comparison.

Neither test should carry a diagnosis alone. Most assessment batteries for suspected labral pathology pair the crank test with the O’Brien test. Add one confirmatory test, usually the biceps load test for SLAP-specific lesions.

Practices assessing overhead athletes get more out of a structured examination template that records the whole battery in one encounter. Checkbox fields with an outcome per test cut documentation time and keep results consistent between clinicians.

Limitations of the crank test

No shoulder special test confirms or excludes labral pathology on its own, and the crank test is no exception. Leaning on it alone risks both over-investigation and missed diagnoses. The main limitations:

• Inter-rater variability: Figures from single-examiner studies do not replicate cleanly in multi-examiner settings. Examiner technique, arm position, and force application all move the result.
• False positives from nearby structures: Acromioclavicular joint pathology, subacromial impingement, and rotator cuff tears all reproduce pain during the crank maneuver. None of them involves the labrum.
• Patient cooperation: Guarding, acute pain, or restricted range of motion can prevent full execution. That produces an uninterpretable result rather than a true negative.
• Severity discrimination: A positive test cannot grade the tear. Stable type I fraying and a type IV bucket-handle lesion look alike on examination. Grading needs imaging.
• Posterior labral tears: Detection accuracy is lower for isolated posterior lesions than for SLAP or anterior tears in some study cohorts.

When to order imaging after a positive crank test

A positive crank test narrows the differential toward labral pathology. It does not replace imaging for definitive diagnosis or surgical planning. The decision pathway in most musculoskeletal and orthopedic settings runs like this:

1. Positive test plus a consistent history: Order an MRI arthrogram of the shoulder as the primary imaging modality. Intra-articular contrast improves sensitivity for SLAP and labral lesions substantially. Non-contrast MRI can miss 30% to 40% of labral pathology.
2. Positive test plus a prior inconclusive MRI: Repeat with an MRI arthrogram if the original scan was non-contrast. Consider CT arthrogram in patients with MRI contraindications.
3. Positive test plus failed conservative care at 6 to 12 weeks: Discussing arthroscopic evaluation is appropriate. Arthroscopy remains the gold standard for diagnosing and grading labral lesions. The decision should involve the surgeon, the imaging findings, and the patient’s functional goals.
4. Negative test plus high clinical suspicion: Do not use a negative result to exclude labral pathology in an overhead athlete. The same holds after a fall on an outstretched hand. Order the arthrogram on the clinical picture instead.

The post-imaging phase is where records tend to slip. A physical therapy EMR with referral templates that pull the examination findings straight into the imaging request cuts both delays and transcription errors.

Clinical documentation and workflow integration

Diagnostic work only counts if the record shows it. Crank test findings need to sit in the note in a reproducible, defensible form. The next practitioner who opens the chart has to be able to use them. The SOAP language below works in most physical therapy and sports medicine records.

Objective field example: “Crank test performed at 90 degrees abduction in scapular plane with axial compression and IR/ER rotation sweep. Positive: familiar anterior shoulder pain reproduced during external rotation phase. No audible click. O’Brien test positive in pronation, negative in supination, so AC joint excluded.”

Assessment field example: “Findings consistent with glenohumeral labral pathology, most likely a SLAP lesion or anterior labral tear. Clinical impression supported by positive crank and O’Brien tests. MRI arthrogram requested to confirm and grade the lesion before a surgical referral decision.”

Consistency across the team matters more than the wording of any single note. Software that supports configurable note templates, structured examination fields, and AI-assisted clinical documentation keeps special test findings recorded the same way by every clinician.

Related shoulder special tests

The crank test is rarely performed alone. The tests below complement it during a shoulder labral assessment, each adding specificity for a different lesion type or location:

A full shoulder battery takes 10 to 15 minutes to perform and document. Recording it as one structured set, rather than five separate free-text notes, is what makes the findings comparable at the follow-up visit.

How Pabau keeps shoulder examination findings consistent

In most practices a special test result lands in a free-text box. It reads clearly to the clinician who wrote it and poorly to the next one. Six months on, nobody can tell whether the crank test was performed at 90 or 160 degrees, or which rotation arc hurt.

Practice management software like Pabau replaces that box with a configurable assessment template. Each special test gets its own field. Arm position, response type, and rotation arc are stored as discrete values instead of prose. Pabau Scribe, our AI scribe, drafts the surrounding narrative from the encounter, so the structured record still reads as a note.

The payoff arrives later. You can filter a patient cohort by test outcome and audit how consistently the battery is performed. A new clinician gets a template that already encodes your protocol. Every Pabau subscription includes these templates, so nothing here is an add-on.

Record shoulder assessments the same way every time

Configurable examination templates, structured special test fields, and AI-drafted referral letters keep your team’s shoulder documentation consistent. See how Pabau fits a physical therapy or sports medicine practice.

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Conclusion

The crank test earns its place as a fast way to raise or lower your suspicion of labral pathology. It does not earn a diagnosis. Its accuracy rises with a consistent examiner, a pre-selected population, and other tests read alongside it. A positive result points to an MRI arthrogram, not to a conclusion.

Two habits are worth taking away. Record the arm position and the rotation arc every time, so the next assessor can reproduce what you found. And check the citation before you quote an accuracy figure, because several numbers in circulation belong to the wrong paper.

The documentation habit is what carries your diagnostic work forward to the next clinician. Structured fields, consistent SOAP language, and templates the whole team uses keep examination quality steady as the practice grows.

Book a demo to see how Pabau records shoulder special test findings for physical therapy and sports medicine teams.

Continue your research

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