Shoulder Orthopaedic Test: Infraspinatus Test

The Infraspinatus Test assesses pain and strength during resisted shoulder external rotation. A positive finding may include familiar posterior or lateral shoulder pain, weakness or inability to resist compared with the other side. Current shoulder examination literature cautions against using rotator cuff special tests as structure-specific diagnostic tools because multiple muscles and tissues contribute to test responses.

Introduction

A client may report shoulder pain during external rotation, throwing, reaching, pulling, pressing or controlling the arm away from the body. They may also describe weakness or fatigue during overhead or rotational movements.

The Infraspinatus Test provides a simple way to document resisted shoulder external rotation symptoms and strength. The result is most useful when pain, weakness, side-to-side difference and compensation are recorded separately.

Quick Summary

Test name: Infraspinatus Test
Body region: Shoulder, posterior rotator cuff
Purpose: Assess pain and strength during resisted shoulder external rotation
Positive finding: Familiar pain, weakness or inability to resist compared with the other side
Negative finding: No meaningful pain or weakness during resisted external rotation
Best used with: External Rotation Lag Sign, Hornblower’s Sign, Empty Can, Full Can, Painful Arc, shoulder ROM and strength testing
Key limitation: It does not isolate the infraspinatus or diagnose a rotator cuff tear on its own

What Is the Infraspinatus Test?

The Infraspinatus Test is a resisted external rotation test for the shoulder. It is commonly performed with the elbow flexed to 90 degrees and the arm held near the side, although variations exist.

The professional applies resistance as the client attempts to externally rotate the shoulder. The main findings are pain, weakness, inability to resist or compensation.

Why It Is Used

The test is used when posterior rotator cuff or external rotation strength is part of the clinical reasoning.

It may help assess:

Rotator cuff-related shoulder pain
External rotation weakness
Posterior shoulder symptoms
Throwing or racquet sport symptoms
Overhead strength limitations
Pain during pulling or pressing tasks
Side-to-side strength differences

What It Assesses

The test assesses resisted external rotation performance in the selected position. It may involve infraspinatus, teres minor, posterior deltoid, scapular control, pain sensitivity and client effort.

It does not isolate one muscle and does not confirm a tear by itself.

Who It Is Useful For

This test may be useful for gym clients, throwers, swimmers, racquet sport athletes, manual workers and clients with shoulder pain or weakness during external rotation or overhead loading.

When to Use This Test

Use when the client can tolerate resisted external rotation and you want to document external rotation strength or symptom response.

When Not to Use or When to Be Cautious

Use caution with acute trauma, suspected fracture, recent dislocation, severe pain, recent surgery, high irritability, neurological symptoms or inability to hold the starting position.

Equipment Required

Chair or standing space
Pain and strength scale
Measurz recording workflow
Optional handheld dynamometer
Optional comparison side notes

Step-by-Step Protocol / Practice

Setup

Position the client sitting or standing upright.

Client position

Place the tested elbow flexed to approximately 90 degrees. The upper arm is usually kept close to the side unless another position is selected.

Examiner position

Stand beside or in front of the client.

Hand placement

Apply resistance at the distal forearm or wrist while monitoring the elbow and shoulder.

Stabilisation

Keep the elbow close to the body if using the standard position. Avoid trunk rotation, shoulder shrugging or elbow extension.

Movement or force direction

Ask the client to rotate the forearm outward while you apply inward resistance.

Instructions

Ask the client to report pain, weakness, fatigue, familiar symptoms or apprehension.

Positive finding

A positive finding is familiar pain, weakness or inability to resist compared with the other side.

Negative finding

A negative finding is no meaningful pain or weakness during resisted external rotation.

Stopping criteria

Stop if pain increases sharply, the client cannot hold the position, symptoms are not tolerated or compensation dominates.

Safety notes

Record pain and weakness separately. Do not assume pain equals structural tearing.

Positive and Negative Test Interpretation

A positive Infraspinatus Test may support posterior rotator cuff or rotator cuff-related shoulder pain reasoning when it reproduces familiar pain or shows clear weakness.

Pain alone does not identify the infraspinatus. Weakness may reflect pain inhibition, fatigue, effort, neurological contribution, tendon-related involvement or broader shoulder function.

A negative test does not exclude rotator cuff pathology, especially if symptoms occur only under higher load, fatigue, speed or overhead positions.

Sensitivity, Specificity and Diagnostic Accuracy

The Infraspinatus Test is used to assess possible infraspinatus tendon involvement in the shoulder. Research suggests it has good sensitivity and moderate specificity, meaning it may be useful for detecting infraspinatus-related shoulder pathology, but it is not accurate enough to use by itself. It is best interpreted alongside the client’s history, symptoms, range of motion, strength testing, and other rotator cuff assessments.

The key study reported sensitivity of 0.90 and specificity of 0.74 for the infraspinatus test, but also concluded that high-resolution ultrasound is often needed to establish a clearer diagnosis.

This means:

• A negative test may help reduce suspicion of infraspinatus involvement.

• A positive test may increase suspicion, especially if there is clear weakness in external rotation.

• However, pain or weakness can come from other shoulder issues, so the result needs to be interpreted with the full assessment.

Reliability and Validity

Reliability depends on elbow position, shoulder position, resistance level, comparison side, client effort and whether pain and weakness are recorded separately.

A 2020 JOSPT viewpoint argued that special tests for rotator cuff-related shoulder pain should not be used as precise tissue-identification tools because commonly used shoulder tests activate multiple muscles and structures.

Common Errors and Limitations

Common errors include allowing trunk rotation, testing with inconsistent elbow position, applying excessive resistance, failing to compare sides, recording pain and weakness as the same result and interpreting the test as a specific tendon test.

Limitations include poor tissue specificity, pain inhibition, effort variation, neurological contribution, fatigue, compensation and overlap with other shoulder presentations.

Practical Applications

Use the Infraspinatus Test to document external rotation pain and strength response. It is most useful when combined with external rotation lag testing, shoulder ROM, rotator cuff strength testing and functional overhead assessment.

How to Record This in Measurz

Record test name, side tested, result, pain score, symptom location, weakness yes/no, elbow position, shoulder position, resistance level, comparison side, compensation, confidence in result and reason for stopping.

Add related findings such as External Rotation Lag Sign, Hornblower’s Sign, Empty Can, Full Can, shoulder ROM, external rotation strength and overhead task symptoms.

Related Tests / Internal Links

External Rotation Lag Sign
Hornblower’s Sign
Empty Can Test
Full Can Test
Painful Arc
Shoulder External Rotation Test
Shoulder Strength Testing
Drop Arm Test

FAQs

What does the Infraspinatus Test assess?

It assesses pain and strength during resisted shoulder external rotation.

What is a positive Infraspinatus Test?

A positive result is familiar pain, weakness or inability to resist compared with the other side.

Does it isolate the infraspinatus?

No. Several shoulder muscles and structures can contribute to the test response.

Can it diagnose a rotator cuff tear?

No. It may support clinical reasoning but does not diagnose a tear on its own.

What should be recorded?

Record side, pain, weakness, elbow position, shoulder position, resistance level and compensation.

Key Takeaways

The Infraspinatus Test assesses resisted shoulder external rotation.
Pain and weakness should be recorded separately.
It does not isolate one tendon or diagnose a tear on its own.
Use it with other rotator cuff and strength findings.
Measurz should capture symptoms, position, weakness and compensation.

References

Micheroli, R., Kyburz, D., Ciurea, A., Dubs, B., Toniolo, M., Bisig, S. P., & Tamborrini, G. (2015). Correlation of findings in clinical and high resolution ultrasonography examinations of the painful shoulder. Journal of Ultrasonography, 15(60), 29–44. https://doi.org/10.15557/JoU.2015.0003

Powell, J. K., & Lewis, J. S. (2020). It is time to put special tests for rotator cuff-related shoulder pain out to pasture. Journal of Orthopaedic & Sports Physical Therapy, 50(5), 222–225. https://doi.org/10.2519/jospt.2020.0606

Zhang, A. L., Palani, P., Kassab, N. S., Terzic, M., Olejnik, M., Wang, S., Tomassini-Lopez, Y., Dean, C., & Shellenberger, R. A. (2024). Evidence-based approach to the shoulder examination for subacromial bursitis and rotator cuff tears: A systematic review and meta-analysis. BMC Musculoskeletal Disorders, 25, 1028. https://doi.org/10.1186/s12891-024-08144-z