title: Does the presence of the palmaris longus tendon influence median nerve function?
abstract: BACKGROUND
  The objective of this study was to determine if the presence or absence of a palmaris longis tendon influenced the function of the median nerve across the wrist. The primary hypothesis was that the presence of a palmaris longus tendon would be associated with more median nerve entrapment at the wrist.
  
  
  METHODS
  This was a cross-sectional study. Subjects were recruited at a screening of dental professionals. The median and ulnar sensory nerve latencies across the wrist (relative prolongation of the median compared with the ulnar) and the presence or absence of the palmaris longus tendon were the primary outcome measures.
  
  
  RESULTS
  A total of 462 subjects were recruited into the study of which 16.2% lacked a palmaris longus tendon. There was no difference in the median nerve function or the percentage with a 0.5 ms prolongation of the median sensory latency when comparing subjects with and without a palmaris longus tendon.
  
  
  CONCLUSIONS
  The presence of a palmaris longus tendon does not influence the median nerve function across the wrist.
authors.affiliation: Ann Arbor Veterans Health System, Ann Arbor, Michigan 48105, USA. rawerner@umich.edu
authors.forename: Robert A
authors.initials: RA
authors.lastname: Werner
authors.forename: Teresa
authors.initials: T
authors.lastname: Spiegelberg
mesh_terms: D050824:Carpal Joints / Q000294:innervation*; D002349:Carpal Tunnel Syndrome / Q000209:etiology / Q000503:physiopathology; D003430:Cross-Sectional Studies; D006801:Humans; D008475:Median Nerve / Q000502:physiology*; D009431:Neural Conduction / Q000502:physiology; D013710:Tendons / Q000033:anatomy & histology*; D014459:Ulnar Nerve / Q000502:physiology; D014953:Wrist / Q000294:innervation