title: Effect of wrist angle on median nerve appearance at the proximal carpal tunnel.
abstract: This study investigated the effects of wrist angle, sex, and handedness on the changes in the median nerve cross-sectional area (MNCSA) and median nerve diameters, namely longitudinal diameter (D1) and vertical diameter (D2). Ultrasound examination was conducted to examine the median nerve at the proximal carpal tunnel in both dominant and nondominant hands of men (n = 27) and women (n = 26). A total of seven wrist angles were examined: neutral; 15°, 30°, and 45° extension; and 15°, 30°, and 45° flexion. Our results indicated sexual dimorphism and bilateral asymmetry of MNCSA, D1 and D2 measurements. MNCSA was significantly reduced when the wrist angle changed from neutral to flexion or extension positions. At flexion positions, D1 was significantly smaller than that at neutral. In contrast, at extension positions, D2 was significantly smaller than that at neutral. In conclusion, this study showed that MNCSA decreased as the wrist angle changed from neutral to flexion or extension positions in both dominant and nondominant hands of both sexes, whereas deformation of the median nerve differed between wrist flexion and extension.
authors: Department of Human Science, Graduate School of Design, Kyushu University, Minami-ku, Fukuoka, Japan.
authors: Ping Yeap
authors: PY
authors: Loh
authors: Department of Human Science, Faculty of Design, Kyushu University, Minami-ku, Fukuoka, Japan.
authors: Satoshi
authors: S
authors: Muraki
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena / Q000502:physiology; D002349:Carpal Tunnel Syndrome / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008475:Median Nerve / Q000000981:diagnostic imaging*; D016059:Range of Motion, Articular / Q000502:physiology; D014463:Ultrasonography; D014953:Wrist / Q000000981:diagnostic imaging*; D014955:Wrist Joint / Q000000981:diagnostic imaging*; D055815:Young Adult