The Phalen’s test is a physical examination technique used by healthcare professionals to help diagnose a common condition affecting the wrist and hand. Also known as the Phalen’s maneuver, this test involves placing the patient’s wrists in a specific position to see if it reproduces certain symptoms. Because it requires no specialized equipment, it is frequently performed quickly during a routine clinic appointment to gauge the likelihood of a nerve compression issue.
What Phalen’s Test Measures
Phalen’s test assists in the diagnosis of Carpal Tunnel Syndrome (CTS), the most common nerve entrapment disorder in the upper extremity. CTS occurs when the median nerve becomes compressed within the carpal tunnel, a narrow passage in the wrist. This passageway is bordered by the wrist bones and covered by the transverse carpal ligament.
The median nerve provides sensation to the thumb, index, middle, and half of the ring finger, and controls some muscles at the base of the thumb. Compression disrupts the nerve’s function, leading to CTS symptoms. The Phalen’s maneuver temporarily increases pressure within the carpal tunnel, exacerbating existing median nerve compression and making symptoms more noticeable.
Performing the Test Maneuver
A healthcare provider administers Phalen’s test by asking the patient to place the backs of their hands together, allowing the wrists to drop into maximum flexion. The patient is instructed to keep their elbows pointed out while maintaining this posture.
The wrists should be bent at approximately a 90-degree angle to effectively narrow the carpal tunnel space. The patient holds this flexed position, most commonly for 60 seconds. The doctor observes the patient and asks them to report any sensations that develop, aiming to see if the sustained wrist flexion triggers the patient’s usual signs of nerve compression.
Understanding the Test Results
A “positive” result occurs if the patient experiences the reproduction of Carpal Tunnel Syndrome symptoms within the 60-second time frame. These symptoms include numbness, tingling, or a burning sensation in the fingers supplied by the median nerve: the thumb, index finger, middle finger, and the thumb-side half of the ring finger.
This symptom occurrence is a physiological response to increased mechanical pressure on the compromised median nerve. Full wrist flexion crowds the carpal tunnel structures, further restricting nerve function. A negative result means the patient holds the position for the full 60 seconds without experiencing these sensations. A quicker onset of symptoms suggests more significant nerve compression.
Clinical Utility and Limitations
Phalen’s test is a screening tool often used alongside a patient’s medical history and other physical assessments, such as Tinel’s sign and the Durkan carpal compression test. It provides a quick indication of nerve irritation, helping to guide the overall diagnostic process.
Research indicates that the accuracy of Phalen’s test can vary significantly, with reported sensitivities—the ability to correctly identify a person with CTS—ranging widely across different studies. The test’s specificity, which is the ability to correctly identify a person without the condition, also shows considerable variation. Because of this variability, a positive result from Phalen’s test alone is usually not sufficient to confirm a diagnosis.
The test is less reliable in very early stages of the condition or in very severe cases where the nerve is already significantly damaged. Clinicians rely on a combination of these provocative maneuvers and electrodiagnostic studies, like nerve conduction velocity tests, to achieve a definitive diagnosis.