Purpose: To assess for carpal tunnel syndrome (CTS).
Test Position: Sitting or standing.
Performing the Test: The examiner places the patient's wrist in maximal extension (but not overpressure), while maintaining the shoulder in neutral and elbow in extension (avoids compressing nerve proximally) and finger extension. This position is maintained for 60 seconds or until numbness and tingling is felt in the median nerve distribution (palmar surface of 1st, 2nd, 3rd, and radial half of 4th digit) - positive test. The examiner should record the number of seconds at which symptoms are produced.
Diagnostic Accuracy: Unknown.
Performing the 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. The position of wrist and finger extension stretches the median nerve and thus adds compression in the carpal tunnel, leading to numbness and tingling in the palmar surface of the 1st, 2nd, 3rd, and radial 1/2 of 4th digits.
References; Neumann, Donald. Kinesiology of the Musculoskeletal System: Foundations for Rehabilitation. 2nd edition. St. Louis, MO: Mosby Elsevier, 2010. 219. Print.