Empty Can Test for Supraspinatus Impingement

What is the Empty Can Test?

The Empty Can test — also known as Jobe’s test or the supraspinatus test — is a physical examination technique used to assess the integrity of the supraspinatus muscle and tendon. It is one of the most commonly performed rotator cuff tests in orthopedic and physical therapy practice. The patient holds the arm in the scapular plane with full internal rotation (thumb down, as if emptying a can) while the examiner applies downward resistance. A positive result is pain and/or weakness during the resisted hold.

Quick Reference

Also known as	Jobe’s test, supraspinatus test, empty beer can test
Structure tested	Supraspinatus muscle and tendon
Patient position	Standing or seated, arm at 90° in scapular plane, full internal rotation
Positive sign	Pain and/or weakness with resisted downward pressure
Sensitivity	~74% (Hegedus et al., 2012)
Specificity	~30% (Hegedus et al., 2012)

What the Empty Can Test Assesses

The Empty Can test is designed to load the supraspinatus muscle and tendon under resisted abduction. By positioning the arm in the scapular plane with full internal rotation, the examiner places the supraspinatus at a mechanical disadvantage — theoretically maximizing its contribution to resisting the downward force and exposing weakness or pain associated with tendon pathology or tears.

The test screens for:

• Supraspinatus tendon tears — partial or full thickness
• Supraspinatus tendinopathy — degenerative or inflammatory changes without frank tear
• Suprascapular nerve neuropathy — which can cause supraspinatus weakness without tendon pathology
• Subacromial pain syndrome — pain component of the test may reflect subacromial impingement rather than tendon integrity

Anatomy: The Supraspinatus

The supraspinatus is one of the four rotator cuff muscles, originating from the supraspinous fossa of the scapula and inserting on the superior facet of the greater tuberosity of the humerus. It passes beneath the coracoacromial arch through the subacromial space, making it the most commonly involved muscle in both impingement syndrome and rotator cuff tears.

The supraspinatus has two primary roles: initiating shoulder abduction (particularly in the first 15–30°) and contributing to glenohumeral compression and stabilization throughout the arc of motion. Weakness or pain in the supraspinatus disrupts both functions, often presenting as difficulty with overhead activities, reaching across the body, or lifting the arm away from the side.

Testing in the scapular plane — approximately 30° anterior to the coronal plane — is functionally significant. This is the plane in which the glenohumeral and scapular joints are most congruent and the supraspinatus is best aligned with its line of pull, making it the most mechanically meaningful position for assessing supraspinatus strength.

How to Perform the Empty Can Test

Starting Position

The patient stands or sits with the arm elevated to 90° in the scapular plane — approximately 30° anterior to the coronal plane. The arm is fully internally rotated so the thumb points downward, mimicking the motion of emptying a beverage can. The elbow remains extended throughout.

Procedure

1. Position the patient’s arm at 90° in the scapular plane with full internal rotation, thumb down.
2. Instruct the patient to hold the arm firmly in position and resist downward pressure.
3. Apply firm, steady downward pressure to the distal forearm or wrist.
4. Observe and note whether the patient reports pain, and compare strength bilaterally.

Bilateral comparison is essential — mild asymmetry in strength may reflect pre-existing dominance differences rather than pathology. A significant strength deficit on the symptomatic side is the most clinically meaningful finding.

Empty Can vs. Full Can Test

The Full Can test uses an identical position in the scapular plane but with the arm in 45° of external rotation — thumb pointing upward. Both tests apply downward resistance at 90° of elevation and screen for supraspinatus pathology.

	Empty Can	Full Can
Arm rotation	Full internal (thumb down)	45° external (thumb up)
Elevation	90° in scapular plane	90° in scapular plane
Positive sign	Pain and/or weakness	Pain and/or weakness
Patient comfort	Often painful at end range	Generally better tolerated

EMG research has shown that neither the empty can nor full can position purely isolates the supraspinatus — the infraspinatus is co-activated in both positions. The Full Can test is generally better tolerated by patients because the externally rotated position moves the greater tuberosity away from the coracoacromial arch, reducing subacromial compression and making pain a more specific finding when it does occur. Many clinicians now prefer the Full Can test for this reason, or use both in combination.

Positive Sign and Interpretation

The Empty Can test is considered positive when the patient reports pain and/or demonstrates significant weakness during resisted downward pressure compared to the uninvolved side.

Pain and weakness carry different clinical implications:

• Weakness without significant pain — more suggestive of a structural tear or suprascapular nerve neuropathy; the tendon or nerve cannot generate sufficient force regardless of pain inhibition
• Pain with preserved strength — more consistent with tendinopathy, bursitis, or impingement; the tendon is intact but inflamed
• Pain and weakness together — raises concern for a significant partial or full-thickness tear, though pain inhibition can also reduce strength in the absence of structural damage

Sensitivity and Specificity

The Empty Can test has been studied in multiple systematic reviews, with a wide range of reported values depending on population, reference standard, and whether pain, weakness, or both are used to define a positive result.

Metric	Value
Sensitivity	~74% (Hegedus 2012); range 25–88% across studies
Specificity	~30% (Hegedus 2012); range 62–89.5% across studies
Interrater reliability	k = 0.43 (moderate)

Values from Hegedus et al. (2012), British Journal of Sports Medicine, and Magee & Sueki (2011), Orthopedic Physical Assessment Atlas and Video.

The practical implication: the Empty Can test has reasonable sensitivity — it catches most supraspinatus pathology when present — but poor specificity, meaning a positive result alone does not confirm a tear. It is best used as a screening tool within a full rotator cuff examination rather than as a standalone diagnostic test. The wide range across studies reflects how heavily the result depends on whether pain or weakness (or both) is used as the criterion for a positive finding.

Clinical Considerations

Limitations

• The Empty Can position places the greater tuberosity directly beneath the coracoacromial arch, which can provoke pain from subacromial impingement or bursitis independent of supraspinatus integrity — reducing specificity for tendon pathology.
• EMG studies have demonstrated that the empty can position co-activates the infraspinatus, meaning the test does not purely isolate supraspinatus function as originally theorized.
• Pain inhibition can produce apparent weakness even in structurally intact tendons, making it difficult to distinguish true tendon insufficiency from pain-limited effort.
• Moderate interrater reliability (k = 0.43) means results can vary between examiners, limiting its use as a standalone measure.

When to Use It

The Empty Can test is appropriate in the evaluation of patients presenting with:

• Anterolateral shoulder pain, particularly with overhead or resisted activity
• Suspected rotator cuff tear — particularly supraspinatus involvement
• Shoulder weakness with difficulty initiating abduction
• Post-traumatic shoulder assessment in falls on outstretched hand or direct impact
• Age-related degenerative rotator cuff pathology in adults over 50

The Empty Can test is most useful as part of a rotator cuff test cluster. When combined with the Painful Arc sign and the drop arm test, a positive cluster significantly increases the post-test probability of a full-thickness supraspinatus tear and reduces the need for immediate imaging in straightforward presentations.

History and Eponym

The Empty Can test is also widely known as Jobe’s test, named after Dr. Frank Jobe (1925–2014), an American orthopedic surgeon best known for pioneering ulnar collateral ligament reconstruction — the procedure now commonly called Tommy John surgery. Jobe described the supraspinatus test as part of his work on shoulder examination in overhead athletes, particularly baseball pitchers. His contributions to shoulder and elbow surgery fundamentally shaped modern sports medicine, and his name remains attached to this test in many clinical and academic settings.

Related Shoulder Tests

• Full Can Test: the alternative supraspinatus assessment performed with external rotation; compare results from both positions
• Drop Arm Test: screens for full-thickness supraspinatus tear when weakness is found on the Empty Can
• Hawkins-Kennedy Test: assess for subacromial impingement contributing to pain on the Empty Can test

See all shoulder orthopedic special tests.

Frequently Asked Questions

What does a positive Empty Can test mean?

A positive Empty Can test — pain and/or significant weakness during resisted downward pressure in the empty can position — suggests supraspinatus pathology, which may include tendinopathy, partial tear, or full-thickness tear. Weakness is the more diagnostically specific finding; pain alone may reflect subacromial impingement or bursitis without structural tendon damage. A positive result warrants further assessment, including imaging if a significant tear is suspected.

What is the difference between the Empty Can and Full Can test?

Both tests use the same scapular plane position at 90° but differ in arm rotation. The Empty Can uses full internal rotation (thumb down); the Full Can uses 45° external rotation (thumb up). The Full Can position reduces subacromial compression, making it better tolerated and potentially more specific for true supraspinatus weakness rather than pain inhibition. EMG research shows both tests co-activate the infraspinatus, so neither purely isolates the supraspinatus.

Why is the scapular plane used for this test?

The scapular plane — approximately 30° anterior to the coronal plane — is where the glenohumeral and scapulothoracic joints are most congruent and the supraspinatus is best aligned with its functional line of pull. Testing in the coronal plane (straight out to the side) creates impingement and requires more deltoid recruitment. The scapular plane position maximizes the supraspinatus contribution to resisting the downward load, making it the most clinically meaningful position for assessing supraspinatus function.

Can the Empty Can test detect a rotator cuff tear?

It can raise suspicion, but cannot confirm one. The test has reasonable sensitivity for supraspinatus pathology but poor specificity — meaning it generates many false positives. Significant objective weakness (not just pain) is the most meaningful finding. MRI or diagnostic ultrasound is required to characterize the extent of any tear. The Empty Can test is best used as a screening tool to guide the decision to image, not as a definitive diagnostic.

Why is it also called Jobe’s test?

The test is named after Dr. Frank Jobe, the orthopedic surgeon who described the maneuver as part of his shoulder examination work with overhead athletes. Jobe is also famous for pioneering ulnar collateral ligament reconstruction — known as Tommy John surgery. Both names (Empty Can test and Jobe’s test) are widely used in clinical and academic settings and refer to the same examination technique.

Video Demonstration

>> Return to the list of Orthopedic Tests of the Shoulder

Other tests for rotator cuff pathology:

• Drop Arm Test
• Gerber’s Lift Off Test
• Hawkins Test / Hawkins-Kennedy Impingement Test
• Neer Impingement Test
• Painful Arc Test