title: Gliding distance of the extensor pollicis longus tendon with respect to wrist positioning: observation in the hands of healthy volunteers using high-resolution ultrasonography.
abstract: METHODS
  Cross-sectional experimental bench.
  
  
  BACKGROUND
  Optimal tendon gliding is necessary for normal thumb function.
  
  
  OBJECTIVE
  Measure the gliding distance of the extensor pollicis longus (EPL) tendons during passive thumb flexion from high-resolution echo images at four wrist positions.
  
  
  METHODS
  Gliding distance of the EPL tendon in zone 4 of the thumb was measured during passive flexion in four different wrist positions in 25 healthy female volunteers. Tendon gliding was evaluated from high-resolution ultrasonography in a frame-by-frame cross-correlation analysis.
  
  
  RESULTS
  Mean gliding distance of the EPL tendon was 1.79, 2.45, 1.09, and 1.36 mm with the wrist positioned in neutral, 30 degrees of extension, 30 degrees of flexion, and 20 degrees of ulnar deviation, respectively. There were statistically significant differences in the gliding distance of the EPL tendon among all of four wrist positions except for that between the wrist flexion and wrist ulnar deviation conditions.
  
  
  CONCLUSIONS
  Wrist extension induces the greatest magnitude EPL tendon gliding.
authors.affiliation: Graduate School of Health Sciences, Sapporo Medical University, Sapporo, Japan.
authors.forename: Min
authors.initials: M
authors.lastname: Chen
authors.forename: Sadako
authors.initials: S
authors.lastname: Tsubota
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Aoki
authors.forename: Ayumu
authors.initials: A
authors.lastname: Echigo
authors.forename: Meng
authors.initials: M
authors.lastname: Han
mesh_terms: D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D009068:Movement / Q000502:physiology*; D013710:Tendons / Q000000981:diagnostic imaging* / Q000502:physiology; D013933:Thumb / Q000502:physiology; D014463:Ultrasonography; D014955:Wrist Joint / Q000000981:diagnostic imaging* / Q000502:physiology; D055815:Young Adult