Phalen’s test is a physical examination technique used as a diagnostic tool in medical assessments. It involves specific movements and positions of the hands and wrists. This test helps healthcare providers evaluate certain conditions affecting the upper limbs.
Purpose of the Test
Phalen’s test is primarily used as an aid in diagnosing Carpal Tunnel Syndrome (CTS). This condition occurs when the median nerve, which runs through a narrow passageway in the wrist called the carpal tunnel, becomes compressed. Compression of this nerve can lead to symptoms in the hand and fingers, including numbness, tingling, or pain, particularly in the thumb, index finger, middle finger, and the radial half of the ring finger. The test aims to temporarily increase pressure on the median nerve within the carpal tunnel, reproducing these characteristic symptoms to help clinicians determine if nerve compression is contributing to a patient’s discomfort.
Performing the Test
To perform Phalen’s test, the individual is asked to sit or stand comfortably. The healthcare provider instructs the patient to press the backs of their hands together, allowing their wrists to fully flex. In this position, the fingers point downwards, and the wrists are bent at approximately a 90-degree angle. This position is maintained for 30 to 60 seconds, though some protocols extend it to one or two minutes. The purpose of this sustained wrist flexion is to increase pressure within the carpal tunnel, which can compress the median nerve and trigger Carpal Tunnel Syndrome symptoms.
Interpreting the Results
The results of Phalen’s test are interpreted based on the patient’s experience during the maneuver. A “positive” Phalen’s test occurs if the patient reports the reproduction or worsening of symptoms such as numbness, tingling, or pain. These symptoms must manifest within the distribution of the median nerve, specifically in the thumb, index, middle, and a portion of the ring finger. Conversely, a “negative” result means the patient experiences no new or intensified symptoms during the test. While a positive result suggests the likelihood of Carpal Tunnel Syndrome, it is important to understand that a positive Phalen’s test alone is not considered a definitive diagnosis for CTS.
Test Reliability and Considerations
The reliability of Phalen’s test as a standalone diagnostic tool varies. It generally exhibits moderate sensitivity (75-80% accuracy) but lower specificity (50-60%), meaning it may produce false-positive results. Therefore, Phalen’s test is typically used with other diagnostic methods for a more accurate assessment. These include a detailed patient history, other physical examination maneuvers like Tinel’s sign, or definitive tests such as nerve conduction studies. Factors like testing technique consistency, patient cooperation, and CTS severity can influence the test’s outcome.