To test for carpal tunnel syndrome (CTS)
Clinically Relevant Anatomy
Formed by the spinal roots C6, C7, C8, T1.
- C6 innervates -->lateral side forearm -->wrist extensors
- C7 innervates --> middle finger -->wrist flexors
- C8 innervates -->medial side of forearm, ring finger and little fingers flexors like
- T1 innervates -->medial side of upper arm
- Innervates: Pronator teres, Palmaris longus, Flexor carpi radialis, Flexor digitorum superficialis, Flexor digitorum profundus (lateral half), Pronator quadratus, Flexor pollicis longus, Abductor pollicis brevis, Opponens pollicis, Flexor pollicis brevis, and Lumbricals 1 and 2[3F]
Summary of CTS
The phalen’s test is a provocative test used in the diagnosis of CTS. This occurs when the median nerve is compressed or squeezed at the wrist. [4C,5F] The pain is often worst at night. Daily activities such as driving and typing may increase the symptoms. [5F] The most common complaints are;
- pain and tingling of hands and fingers
- numbness in the fingers (specifically the thumb, forefinger and a part of the middle finger)
- pain in or near the wrist. [9F]
- pain extending into the arm (less frequent)
- skin lesions in the territory of the median nerve are possible due to compression of blood vessels in the carpal tunnel [6C]
The patient places her flexed elbows on a table, allowing her wrists to fall into maximum flexion. The patient is asked to push the dorsal surface of her hands together and hold this position for 30-60 seconds. This position will increase the pressure in the carpal tunnel, in effect compressing the median nerve between the transverse carpal ligament and the anterior border of the distal end of the radius.
Another way to describe the standard Phalen's test: the patient leaves his / her elbows bent between 0 ° -30 °. Then the therapist asks the patient to supinate his / her forearm. After this the therapist carries a maximum palmar flexion of the wrist and holds it for 60 seconds. During the test the patient will be asked to explain each 15 seconds what she feels. [7C]
Reverse Phalen's test. The patient maintains a position of full wrist and finger extension for two minutes. The pressure on the carpal tunnel increases after 10 seconds (compared to 20-30 seconds for the standard Phalen test). The longer the position is held, the greater the pressure on the wrist and carpal tunnel.
In a study comparing the changes in pressure between Phalen and Reverse Phalen's tests, it was noted that the average pressure change for Phalen's test was 4 mmHg in two minutes versus 34 mmHg at one minute and 42 mmHg at two minutes for the Reverse Phalen test [1C] The Reverse Phalen's test may therefore be a more appropriate clinical test for truly compressing the carpal tunnel and provoking symptoms of CTS.
Positive test: Both Phalen test and Reverse Phalen's tests are considered positive when the patient's symptoms are reproduced, test gives the same symptoms as that experienced with carpal tunnel syndrome, namely paresthesia (buring, tingling, numbness) in the distribution of the median nerve. 
Negative test: Patient feels no pain or any other symptom, even if the motion is maintained for three minutes or longer. [2A]
Reliability: One study has shown that the intra-rate reliability standard is moderate and that the inter-rater reliability appears to be good. [10C] From another study shows the Phalen test sensitivity (0.64), specificity (0.75), positive likelihood ratio (2.54) and negative likelihood ratio (0.49) were measured. Therefore, when a positive Phalen's test is finding it is more likely that these changes are associated with nerve conduction studies in accordance with the carpal tunnel syndrome. [11C]
Due to the wide ranges of Sen and Sp in the literature, it has been concluded that the Phalen's maneuver should only be used in an adjunctive manner in diagnosing carpal tunnel syndrome. 
- Development of a Clinical Prediction Rule for the Diagnosis of Carpal Tunnel Syndrome.
- Clinical diagnosis of carpal tunnel syndrome: old tests-new concepts.
- Carpal Tunnel Syndrome: Provocative Maneuvers.
- Magee DJ. 2002, Orthopedic Physical Assessment, 4th edition, Philadephia: Saunders
- Urbano, FL. Tinel's Sign and Phalen's Maneuver: Physical Signs of Carpal Tunnel Syndrome. Hosptial Physician 2000; Jul,39-44. http://www.turner-white.com/pdf/hp_jul00_tinel.pdf (accessed 20Dec2009)
- Wikipedia-Phalens Maneuver. http://www.enwikipedia.org/wiki/Phalen's_maneuver (accessed 20 Dec 2009)