title: Finger position alters the median nerve properties within the carpal tunnel: a pre-post MRI comparison study.
abstract: OBJECTIVE
  The purpose of this study was to compare the properties of the median nerve and the flexor retinaculum within the carpal tunnel with Magnetic Resonance Imaging (MRI) under two conditions: (a) fingers extended, and (b) fingers in an isometric squeeze grip.
  
  
  METHODS
  Thirty-Four volunteers participated in this experimental study. The flexor retinaculum and median nerve characteristics were measured during both conditions using MRI.
  
  
  RESULTS
  The isometric squeeze grip condition resulted in significant palmar bowing of the flexor retinaculum (t = 7.67, p<.001), a significant flattening-ratio of the median nerve (t = 4.308, p<.001), and no significant decrease in the cross-sectional area of the median nerve (t = 2.508, p = 0.017).
  
  
  CONCLUSIONS
  The isometric squeeze grip condition resulted in anatomical deformations within the carpal tunnel, possibly explained by the lumbrical muscles incursion into the carpal tunnel during finger flexion.
authors.affiliation: Occupational Therapy Department, Faculty of Allied Health Sciences, Kuwait University, Jabriah, Kuwait.
authors.forename: Mohammed Shaban
authors.initials: MS
authors.lastname: Nadar
authors.forename: Mohsen H
authors.initials: MH
authors.lastname: Dashti
authors.forename: Jigimon
authors.initials: J
authors.lastname: Cherian
mesh_terms: D000293:Adolescent; D000328:Adult; D005385:Fingers / Q000294:innervation* / Q000502:physiology*; D018737:Hand Strength / Q000502:physiology*; D006801:Humans; D007537:Isometric Contraction; D008022:Ligaments / Q000033:anatomy & histology / Q000294:innervation / Q000502:physiology; D008279:Magnetic Resonance Imaging; D008475:Median Nerve / Q000502:physiology*; D009431:Neural Conduction; D014953:Wrist / Q000002:abnormalities / Q000033:anatomy & histology* / Q000294:innervation*; D055815:Young Adult