Hornblower’s Sign: How to Perform the Test, Interpret Results and Accuracy
Hornblower’s sign is a physical examination test of the shoulder. It helps clinicians assess the teres minor muscle, a small but functionally important part of the posterior rotator cuff. The test is quick, needs no equipment and is useful when a posterior rotator cuff tear is suspected. This article covers what the test is used for, how to perform it, how to interpret it and how accurate it is.
What Is Hornblower’s Sign Used For?
Hornblower’s sign is used to detect teres minor muscle pathology. Together with the infraspinatus, the teres minor is the main external rotator of the glenohumeral joint. When the teres minor is torn or degenerated, active external rotation with the arm elevated becomes weak or impossible.
The sign was described by Walch and colleagues in a study of patients who had surgery for combined supraspinatus and infraspinatus tears. They linked the sign to advanced fatty degeneration of the teres minor, which has previously been associated with poorer results after reconstructive surgery [1]. The test therefore helps the examiner judge how much of the posterior cuff is compromised, and it can inform surgical planning.
How to Perform Hornblower’s Sign
The test is simple to run. Follow these steps:
- Position the patient sitting or standing, with the examiner able to support the arm.
- Bring the shoulder to 90 degrees of abduction.
- Place the shoulder in 90 degrees of external rotation, with the elbow flexed.
- Ask the patient to hold this position actively once the examiner releases support.
- Compare with the opposite shoulder and observe whether the position can be maintained.
A step-by-step description of the technique is also available on the Orthofixar Hornblower’s sign page [2].
Interpreting the Result: What Is a Positive Test?
The test is positive if the arm falls into internal rotation when the examiner lets go. The patient cannot actively hold the externally rotated position, which points to insufficient teres minor function. In practice the arm drops, and the patient may bring the hand toward the mouth with the elbow lifted. This is the “hornblower” posture that gives the sign its name. A negative test means the patient can maintain the position, suggesting the teres minor is working well enough to hold external rotation.
Test Accuracy: Sensitivity and Specificity
In the original study of 54 patients, Hornblower’s sign had a sensitivity of 100% and a specificity of 93%. These figures refer to the detection of Goutallier stage 3 or 4 fatty degeneration of the teres minor, the grades considered irreparable [1].
- High sensitivity (100%): every patient with advanced teres minor degeneration in that series had a positive sign. A negative result makes severe teres minor degeneration unlikely.
- High specificity (93%): few patients without advanced degeneration had a positive sign. A positive result therefore strongly suggests teres minor involvement.
The same study found that the dropping sign, a related test, detected infraspinatus degeneration with 100% sensitivity and 100% specificity [1]. Using the two signs together gives a fuller picture of posterior cuff function.
A Useful Clinical Finding: Teres Minor Hypertrophy
Walch and colleagues also noted that the teres minor was hypertrophied in seven patients. When intact, this muscle can provide useful function for activities of daily living in patients with rotator cuff tears [1]. This is one reason the muscle’s status matters when counselling patients and planning treatment.
Limitations of the Evidence
The reported accuracy comes from a single surgical series of 54 patients, all of whom had combined supraspinatus and infraspinatus tears [1]. The reference standard was fatty degeneration of the teres minor, not an isolated tear. The numbers may therefore not transfer to the general population or to patients without a large cuff tear. Hornblower’s sign should be interpreted alongside the history, other cuff tests and imaging, rather than used alone.
Frequently Asked Questions (FAQ)
What is Hornblower’s sign used for?
It is used to assess teres minor pathology, particularly in suspected posterior rotator cuff tears.
How do you perform Hornblower’s sign?
Bring the shoulder to 90 degrees of abduction and 90 degrees of external rotation, then ask the patient to hold the position.
What is a positive Hornblower’s sign?
The test is positive when the arm falls into internal rotation because the patient cannot hold the position.
How accurate is Hornblower’s sign?
In the original study, sensitivity was 100% and specificity was 93% for irreparable fatty degeneration of the teres minor [1].
Does a positive test always mean a teres minor tear?
No. It indicates insufficient teres minor function and should be confirmed with the full clinical picture and imaging.
What other test is used with Hornblower’s sign?
The dropping sign, which assesses the infraspinatus, is commonly paired with it [1].
Why does teres minor status matter for surgery?
Advanced fatty degeneration of the teres minor has been associated with poorer outcomes after reconstructive surgery [1].
References
- Walch G, Boulahia A, Calderone S, Robinson AH. The “dropping” and “hornblower’s” signs in evaluation of rotator-cuff tears. J Bone Joint Surg Br. 1998;80(4):624-8. doi:10.1302/0301-620x.80b4.8651. PubMed
- Hornblower’s Sign. Orthofixar. https://orthofixar.com/special-test/hornblower-sign/