Position of the wrist associated with the lowest carpal-tunnel pressure: implications for splint design

• Published in: Journal of bone and joint surgery. American volume 1995-11, Vol.77 (11), p.1695-1699
• Main Authors: Weiss, N D, Gordon, L, Bloom, T, So, Y, Rempel, D M
• Format: Article
• Language: English
• Subjects: Adult; Biological and medical sciences; Carpal Tunnel Syndrome - physiopathology; Carpal Tunnel Syndrome - therapy; Case-Control Studies; Cranial nerves. Spinal roots. Peripheral nerves. Autonomic nervous system. Gustation. Olfaction; Female; Humans; Immobilization - adverse effects; Male; Median Nerve - physiopathology; Medical sciences; Middle Aged; Nervous system (semeiology, syndromes); Neurology; Posture; Range of Motion, Articular; Splints - adverse effects; Transducers, Pressure; Ulnar Nerve - physiopathology; Wrist - physiopathology
• ISSN: 0021-9355; 1535-1386
• DOI: 10.2106/00004623-199511000-00008

Increased carpal-tunnel pressure has been implicated in the pathophysiology of carpal tunnel syndrome, but it is not known whether splints that immobilize the wrist in a functional position of extension minimize carpal tunnel pressure. To determine the position of the wrist that results in the lowest carpal-tunnel pressure, twenty control subjects and four patients who had carpal tunnel syndrome were evaluated with use of a new, dynamic method that continuously measures carpal tunnel pressure throughout the range of motion of the wrist. The pressure was measured by means of a pressure transducer connected to a flexible catheter that had been inserted into the carpal canal. The position of the wrist was measured simultaneously with use of a two-axis electrogoniometer. Aided by a computer monitor that displayed a moving line of real-time carpal-tunnel pressure, each subject was instructed to move the wrist throughout the range of motion and to adjust it to the position that corresponded to the lowest carpal-tunnel pressure. For the control subjects, the lowest carpal-tunnel pressure averaged 8 +/- 4 millimeters of mercury (1.07 +/- 0.53 kilopascals), and the average position of the wrist associated with the lowest pressure was 2 +/- 9 degrees of extension and 2 +/- 6 degrees of ulnar deviation.