title: Position of the wrist associated with the lowest carpal-tunnel pressure: implications for splint design.
abstract: 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.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Ergonomics Program, University of California at San Francisco 94804, USA.
authors.forename: N D
authors.initials: ND
authors.lastname: Weiss
authors.forename: L
authors.initials: L
authors.lastname: Gordon
authors.forename: T
authors.initials: T
authors.lastname: Bloom
authors.forename: Y
authors.initials: Y
authors.lastname: So
authors.forename: D M
authors.initials: DM
authors.lastname: Rempel
mesh_terms: D000328:Adult; D002349:Carpal Tunnel Syndrome / Q000503:physiopathology* / Q000628:therapy*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007103:Immobilization / Q000009:adverse effects; D008297:Male; D008475:Median Nerve / Q000503:physiopathology; D008875:Middle Aged; D011187:Posture; D016059:Range of Motion, Articular; D013165:Splints / Q000009:adverse effects; D014160:Transducers, Pressure; D014459:Ulnar Nerve / Q000503:physiopathology; D014953:Wrist / Q000503:physiopathology*