The Phalen’s test is a straightforward, non-invasive maneuver used by healthcare providers during a physical examination to screen for nerve compression in the wrist. Also known as Phalen’s sign or Phalen’s maneuver, it is a preliminary step in evaluating patients who report symptoms of numbness and tingling in their hands. The test works by temporarily increasing pressure on the median nerve pathway, aiming to reproduce the patient’s existing discomfort. It is a simple, no-equipment procedure that offers immediate, though not definitive, insight into a potential diagnosis.
The Condition Evaluated
The primary condition Phalen’s test screens for is Carpal Tunnel Syndrome (CTS), which results from the compression of the median nerve as it passes through the carpal tunnel, a narrow passageway in the wrist. This tunnel is formed by the carpal bones and the transverse carpal ligament. Swelling or inflammation of the tissues within this confined space can put pressure on the median nerve.
The median nerve is responsible for sensation in the thumb, index finger, middle finger, and the thumb-side half of the ring finger, as well as providing motor function to some muscles at the base of the thumb. Consequently, CTS symptoms typically manifest as numbness, tingling, and pain in this specific nerve distribution. Many individuals experience these sensations worsening at night, often waking them from sleep, and they may resort to “shaking out” their hands to find relief.
As the syndrome progresses, patients may notice weakness in their hand, which can lead to clumsiness or difficulty gripping small objects. While repetitive hand or wrist motions are frequently associated with CTS, other factors like fluid retention, inflammatory conditions such as rheumatoid arthritis, and wrist fractures can contribute to the increased pressure on the median nerve.
How the Test is Performed
The Phalen’s test is conducted by asking the patient to place the backs of their hands together, allowing their wrists to fully flex. The fingers should be pointing downward, resembling an upside-down “praying hands” position, which achieves maximum flexion. The patient holds this static position, often at chest or waist level, for a set period.
The standard duration for holding the position is between 30 and 60 seconds. This forced wrist flexion mechanically narrows the carpal tunnel space, increasing the pressure inside the tunnel. This stresses the median nerve by compressing it against the surrounding structures, mimicking the pressure changes that cause symptoms in daily life. The healthcare provider carefully observes the patient for the onset of symptoms while the position is maintained.
Interpreting the Results
The result of the Phalen’s test is classified as either positive or negative. A positive test is defined by the reproduction or worsening of the patient’s characteristic symptoms—numbness, tingling, or pain—specifically in the median nerve distribution. The faster these symptoms appear within the 60-second limit, the more likely median nerve compression is present.
A negative result occurs if the patient holds the position for the full 60 seconds without experiencing any new or exacerbated symptoms. While a positive result suggests the presence of Carpal Tunnel Syndrome, the test is not a definitive diagnosis. The Phalen’s test is considered a screening tool, which must be interpreted alongside the patient’s clinical history and other physical examination findings.
Confirmation of CTS often requires additional testing, such as electrodiagnostic studies like nerve conduction studies. These studies measure how well the median nerve transmits electrical signals, providing objective data on nerve function and the severity of the compression. A positive Phalen’s test serves as an indicator for the need for further diagnostic evaluation.