Ulnocarpal Stress Test: Procedure, Positive Signs & Clinical Significance

The Ulnocarpal Stress Test, also known as Nakamura’s Ulnar Stress Test, is a clinical examination maneuver used to evaluate ulnar-sided wrist pain and identify possible abnormalities involving the ulnocarpal joint and surrounding structures.

This provocative orthopedic test is particularly useful when evaluating patients with suspected ulnar impaction syndrome, triangular fibrocartilage complex (TFCC) injuries, lunotriquetral ligament tears, or ulnocarpal arthritis.

Originally described by Nakamura and colleagues, the examination combines axial compression, wrist ulnar deviation, and forearm rotation to reproduce symptoms arising from structures on the ulnar side of the wrist.

Although the Ulnocarpal Stress Test is a valuable screening examination, a positive finding does not establish a specific diagnosis. Results must be interpreted alongside the patient’s history, other physical examination findings, and appropriate diagnostic imaging.

What Is the Purpose of the Ulnocarpal Stress Test?

The primary purpose of the Ulnocarpal Stress Test is to identify potentially symptomatic structures responsible for pain along the ulnar (little-finger) side of the wrist.

The maneuver increases mechanical stress across the ulnocarpal articulation and the triangular fibrocartilage complex, helping clinicians reproduce pain associated with several wrist conditions.

The test is commonly used in evaluating the following disorders:

1. Ulnar Impaction Syndrome

Ulnar impaction syndrome, also called ulnocarpal abutment syndrome, occurs when excessive loading between the distal ulna, TFCC, and ulnar carpal bones contributes to degeneration and pain.

It is frequently associated with positive ulnar variance, in which the distal ulna projects farther distally than the radius. However, ulnar impaction can also occur with neutral or negative ulnar variance.

Patients may report discomfort during gripping, lifting, or activities involving forearm rotation. The Ulnocarpal Stress Test can reproduce symptoms by increasing compression across the affected region.

2. Triangular Fibrocartilage Complex (TFCC) Injuries

The TFCC is an important stabilizing and load-transmitting structure on the ulnar side of the wrist. It contributes to distal radioulnar joint stability and helps distribute forces through the ulnocarpal articulation.

Traumatic or degenerative TFCC injuries may cause wrist pain, clicking, weakness, and discomfort during rotational movements.

A positive Ulnocarpal Stress Test can raise suspicion of TFCC pathology, but it cannot reliably distinguish a TFCC tear from other causes of ulnar-sided wrist pain.

3. Lunotriquetral Ligament Injuries

The lunotriquetral ligament connects the lunate and triquetrum, two carpal bones located near the ulnar side of the wrist.

Ligament damage can produce pain, mechanical symptoms, and carpal instability. Axial compression combined with wrist deviation and forearm rotation may reproduce discomfort in patients with these injuries.

4. Ulnocarpal Arthritis

Degenerative or inflammatory changes affecting the ulnocarpal articulation may produce pain when the joint is mechanically loaded.

Consequently, individuals with ulnocarpal arthritis may demonstrate a positive stress test, particularly when compression and rotation aggravate the affected joint surfaces.

How to Perform the Ulnocarpal Stress Test

The Ulnocarpal Stress Test procedure is performed with the patient seated and the affected upper extremity accessible to the examiner.

Patient Position

1. Ask the patient to sit comfortably with the affected arm supported as needed.
2. Position the elbow at approximately 90 degrees of flexion.
3. Maintain the forearm initially in neutral rotation, midway between pronation and supination.
4. Place the wrist in maximum comfortable ulnar deviation, directing the hand toward the little-finger side.

Examiner Technique

1. Stabilize the patient’s forearm while maintaining appropriate control of the hand and wrist.
2. Apply controlled axial compression through the hand toward the wrist, increasing loading across the ulnocarpal articulation.
3. Maintain the wrist in ulnar deviation while gently rotating the forearm through pronation and supination.
4. Observe the patient’s response during compression and rotational movements.
5. Ask whether the maneuver reproduces their usual wrist pain and identify the exact location of discomfort.

The examination should be performed gently, without forceful manipulation. Excessive loading is unnecessary, particularly in patients with acute injuries or marked pain.

What Is a Positive Ulnocarpal Stress Test?

A positive Ulnocarpal Stress Test occurs when axial compression and passive forearm rotation reproduce the patient’s familiar pain on the ulnar side of the wrist.

Pain may become more pronounced during pronation or supination while the wrist remains in ulnar deviation.

A positive response may indicate underlying pathology such as:

• Ulnocarpal impaction syndrome
• TFCC tears or degeneration
• Lunotriquetral ligament injuries
• Ulnocarpal arthritis

A painful mechanical click may accompany the symptoms, but pain reproduction is the principal positive finding. A painless click alone should not be interpreted as a positive test.

A negative test means that the maneuver does not reproduce the patient’s characteristic symptoms. However, a negative result does not definitively exclude TFCC injury or other wrist disorders.

Clinical Accuracy and Diagnostic Value

The Ulnocarpal Stress Test is generally considered a useful provocative examination for detecting ulnar-sided wrist pathology, although its diagnostic specificity is limited.

In their original 1997 study, Nakamura and colleagues evaluated 45 patients with persistent ulnar-sided wrist pain and positive Ulnocarpal Stress Tests. Wrist arthroscopy identified underlying abnormalities in all 45 selected patients.

The final diagnoses included ulnocarpal abutment syndrome, traumatic triangular fibrocartilage tears, lunotriquetral ligament injuries, arthritis, and other intra-articular abnormalities.

However, because this study included only patients with positive tests, its findings should not be interpreted as demonstrating 100% sensitivity or specificity.

Subsequent research has reinforced the limitation that the Ulnocarpal Stress Test may be positive in several different wrist disorders. Therefore, it is most useful as part of a comprehensive examination rather than as an isolated diagnostic tool.

Clinical interpretation: A positive test supports suspicion of ulnar-sided wrist pathology but cannot independently confirm ulnar impaction syndrome or a TFCC tear.

Additional Examination and Diagnostic Imaging

When the Ulnocarpal Stress Test is positive, further clinical evaluation can help determine the underlying cause.

A comprehensive wrist assessment may include the ulnar fovea sign to evaluate suspected TFCC-related pathology, lunotriquetral ballottement testing to assess ligament injury, and distal radioulnar joint stability testing when instability is suspected.

Imaging may also be appropriate depending on the clinical presentation.

Plain wrist radiographs can demonstrate fractures, degenerative changes, and ulnar variance. Magnetic resonance imaging (MRI) can provide additional information about the TFCC, ligaments, cartilage, and other soft tissues.

Wrist arthroscopy may be considered in selected patients when the diagnosis remains uncertain or when surgical treatment is being planned. It is not automatically required following a positive stress test.

Frequently Asked Questions (FAQ)

What does the Ulnocarpal Stress Test assess?

The Ulnocarpal Stress Test assesses pain provoked by mechanical loading of the ulnocarpal region. It is used to screen for disorders such as ulnar impaction syndrome, TFCC injuries, lunotriquetral ligament damage, and arthritis.

Is the Ulnocarpal Stress Test the same as Nakamura’s Test?

Yes. The Ulnocarpal Stress Test is commonly called Nakamura’s Ulnar Stress Test, after Nakamura and colleagues, who published an influential clinical study describing its usefulness in assessing ulnar-sided wrist pain.

What indicates a positive Ulnocarpal Stress Test?

A positive result is characterized by reproduction of the patient’s typical ulnar-sided wrist pain during axial loading and passive pronation-supination with the wrist maintained in ulnar deviation.

Can the Ulnocarpal Stress Test diagnose a TFCC tear?

No. Although TFCC tears can produce a positive result, the test is not sufficiently specific to confirm a TFCC injury independently. Additional examination findings and imaging may be necessary.

Is the Ulnocarpal Stress Test specific for ulnar impaction syndrome?

No. The test may be positive in ulnar impaction syndrome, but similar findings can occur with TFCC tears, lunotriquetral ligament injuries, and wrist arthritis. Therefore, a positive result must be interpreted in the broader clinical context.

What is the difference between the Ulnocarpal Stress Test and the ulnar fovea sign?

The Ulnocarpal Stress Test uses compression and rotational loading to provoke wrist pain. In contrast, the ulnar fovea sign evaluates localized tenderness by palpating the soft-tissue region near the ulnar styloid. The two examinations provide complementary information.

Can a negative Ulnocarpal Stress Test rule out wrist pathology?

No. A negative result does not reliably exclude a TFCC tear, ulnar impaction syndrome, or another cause of ulnar-sided wrist pain. The findings should always be considered alongside the patient’s symptoms, history, and other investigations.

When should further imaging be considered?

Further imaging may be appropriate when pain persists, when a significant structural injury is suspected, or when the findings of the clinical examination are inconclusive. Radiographs and MRI are commonly used depending on the suspected diagnosis.

Conclusion

The Ulnocarpal Stress Test (Nakamura’s Test) is a practical clinical examination for identifying possible causes of ulnar-sided wrist pain.

By combining axial compression, maximum comfortable ulnar deviation, and passive pronation-supination, the examiner can reproduce symptoms associated with ulnar impaction syndrome, TFCC injuries, lunotriquetral ligament damage, and ulnocarpal arthritis.

A positive finding is defined primarily by reproduction of the patient’s characteristic ulnar wrist pain. Because the test has limited specificity, it should be used as a screening maneuver within a comprehensive wrist examination, supported by appropriate imaging when indicated.

References

1. Nakamura R, Horii E, Imaeda T, et al. The ulnocarpal stress test in the diagnosis of ulnar-sided wrist pain. Journal of Hand Surgery (British Volume). 1997;22(6):719–723. PubMed.
2. Vezeridis PS, Yoshioka H, Han R, Blazar P. Ulnar-sided wrist pain. Part I: Anatomy and physical examination. Skeletal Radiology. 2010;39:733–745. NCBI/PubMed Central.
3. Clinical and Radiographic Evaluation of Ulnar-Sided Wrist Pain. Current Reviews in Musculoskeletal Medicine. 2022. NCBI/PubMed Central.
4. Ulnar-sided wrist pain: a prospective analysis of diagnostic clinical tests. 2021. PubMed.
5. Guidelines for the Diagnosis and Treatment of Ulnar Impaction Syndrome (2024). Journal of Wrist Surgery. NCBI/PubMed Central.
6. Ulnar-Sided Wrist Pain: A Diagnostic Evaluation Guide From 30-Plus Years of Experience. 2024. NCBI/PubMed Central.
7. Orthofixar. Ulnocarpal Stress Test: Procedure, Positive Findings, and Clinical Considerations. Orthofixar.com.