Purpose: To assess for carpal tunnel syndrome (CTS).
Test Position: Sitting.
Performing the Test: With the patient's arm in supination, the examiner applies pressure with his/her thumbs over the median nerve within the carpal tunnel. This is located just distal to the wrist crease. A positive test occurs when the patient complains numbness and tingling in the median nerve distribution within 30 seconds. The examiner records the time of onset for the symptoms.
Diagnostic Accuracy: Sensitivity: .87; Specificity: .9 ("A new diagnostic test for carpal tunnel syndrome"). Sensitivity: .525; Specificity: .618 ("Carpal compression test and pressure provocative tests in veterans with median-distribution paresthesias"). Importance of Test: According to Neumann, the carpal tunnel is formed by the palmar surface of the carpal bones (scaphoid, lunate, triquetrum, pisiform, trapezium, trapezoid, capitate, hamate) and the transverse carpal ligament. The transverse carpal ligament attaches to the pisiform and hook of the hamate on the ulnar side and the tubercles of the trapezium and scaphoid on the radial side. These borders create the carpal tunnel through which the tendons of the flexor digitorum profundus, flexor digitorum superficialis, flexor pollicis longus and median nerve travel. This is not a wide space at all. When pressure is increased in this area, people typically feel numbness and tingling on the palmar side of the thumb, 2nd, 3rd, and radial half of the 4th digit. Note: symptoms felt in the palm of the hand indicate pathology proximal to the carpal tunnel. This test looks to recreate that highly-pressurized condition by applying pressure with the examiner's thumbs, which decreases space in the carpal tunnel.
Note: these tests should only be performed by properly trained health care practitioners.
References: Durkan JA. "A new diagnostic test for carpal tunnel syndrome." J Bone Joint Surg AM 1991 April; 73(4): 535-538.
Kaul MP, Pagel KJ, Wheatley MJ, Dryden JD. "Carpal compression test and pressure provocative tests in veterans with median-distribution paresthesias." Muscle Nerve 2001 January; 24(1): 107-111.
Neumann, Donald. Kinesiology of the Musculoskeletal System: Foundations for Rehabilitation. 2nd edition. St. Louis, MO: Mosby Elsevier, 2010. 219. Print.