title: Altered median nerve deformation and transverse displacement during wrist movement in patients with carpal tunnel syndrome.
abstract: OBJECTIVE
  Carpal tunnel syndrome (CTS) is the most common peripheral nerve entrapment syndrome. Strong pinch or grip with wrist flexion has been considered a risk factor for CTS. Studying median nerve displacement during wrist movements may provide useful information about median nerve kinematic changes in patients with CTS. The purpose of this study was to evaluate the deformability and mobility of the median nerve in patients with CTS compared to healthy subjects.
  
  
  METHODS
  Dynamic ultrasound images were obtained in 20 affected wrists of 13 patients with CTS. Results were compared to complementary data obtained from both wrists of 10 healthy subjects reported in a previous study. Shape and position of initial and final median nerve were measured and analyzed for six defined wrist movements. The deformation ratios for each movement were defined as the median nerve area, perimeter, and circularity of the final position normalized by respective values assessed in the initial position. The median nerve displacement vector and magnitude were also calculated.
  
  
  RESULTS
  The deformation ratio for circularity was significantly less in patients with CTS compared to healthy subjects during wrist flexion (P < .05). The mean vector of median nerve displacement during wrist flexion was significantly different between patients with CTS and healthy subjects (P < .05). The displacement magnitude of the median nerve was found to be less in patients with CTS compared to healthy subjects during most movements, with the exception of wrist extension with fingers extended.
  
  
  CONCLUSIONS
  Patients with CTS differ from normal subjects with regard to mobility and deformability of the median nerve.
authors.affiliation: Biomechanics Laboratory, Division of Orthopedic Research, Mayo Clinic, 200 1st St SW, Rochester, MN 55905; Tendon and Soft Tissue Biology Laboratory, Division of Orthopedic Research, Mayo Clinic, Rochester, MN.
authors.forename: Yuexiang
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Biomechanics Laboratory, Division of Orthopedic Research, Mayo Clinic, 200 1st St SW, Rochester, MN 55905; Tendon and Soft Tissue Biology Laboratory, Division of Orthopedic Research, Mayo Clinic, Rochester, MN.
authors.forename: Anika
authors.initials: A
authors.lastname: Filius
authors.affiliation: Biomechanics Laboratory, Division of Orthopedic Research, Mayo Clinic, 200 1st St SW, Rochester, MN 55905; Tendon and Soft Tissue Biology Laboratory, Division of Orthopedic Research, Mayo Clinic, Rochester, MN.
authors.forename: Chunfeng
authors.initials: C
authors.lastname: Zhao
authors.affiliation: Biomechanics Laboratory, Division of Orthopedic Research, Mayo Clinic, 200 1st St SW, Rochester, MN 55905; Tendon and Soft Tissue Biology Laboratory, Division of Orthopedic Research, Mayo Clinic, Rochester, MN.
authors.forename: Sandra M
authors.initials: SM
authors.lastname: Passe
authors.affiliation: Biomechanics Laboratory, Division of Orthopedic Research, Mayo Clinic, 200 1st St SW, Rochester, MN 55905; Tendon and Soft Tissue Biology Laboratory, Division of Orthopedic Research, Mayo Clinic, Rochester, MN.
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Thoreson
authors.affiliation: Biomechanics Laboratory, Division of Orthopedic Research, Mayo Clinic, 200 1st St SW, Rochester, MN 55905; Tendon and Soft Tissue Biology Laboratory, Division of Orthopedic Research, Mayo Clinic, Rochester, MN.
authors.forename: Kai-Nan
authors.initials: KN
authors.lastname: An
authors.affiliation: Biomechanics Laboratory, Division of Orthopedic Research, Mayo Clinic, 200 1st St SW, Rochester, MN 55905; Tendon and Soft Tissue Biology Laboratory, Division of Orthopedic Research, Mayo Clinic, Rochester, MN. Electronic address: pamadio@mayo.edu.
authors.forename: Peter C
authors.initials: PC
authors.lastname: Amadio
mesh_terms: D000328:Adult; D002349:Carpal Tunnel Syndrome / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D055119:Elastic Modulus; D005260:Female; D006801:Humans; D008297:Male; D008475:Median Nerve / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D008875:Middle Aged; D009038:Motion; D009068:Movement; D016059:Range of Motion, Articular; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014463:Ultrasonography; D014955:Wrist Joint / Q000000981:diagnostic imaging* / Q000503:physiopathology*
keywords: Ultrasound; carpal tunnel syndrome; median nerve