title: Tactile sensibility on the fingernail.
abstract: OBJECTIVE
  To measure tactile discrimination (static and moving 2-point discrimination) and threshold levels (Weinstein enhanced sensory test) over the nail plate in normal subjects and compare these values with those at the corresponding finger pulps.
  
  
  METHODS
  Tactile discrimination and threshold values over the nail plates and finger pulps were measured on 300 digits in 30 healthy subjects with a mean age of 23 years. Subjects with cosmetic nail modifications, injuries, neurological deficits, dermatological conditions, or history of upper limb surgery were excluded. Equivalence testing was conducted to look for clinical equivalence between values obtained at both sites.
  
  
  RESULTS
  The mean static 2-point discrimination, moving 2-point discrimination, and threshold value over the human nail were 6.7 mm, 2.4 mm, and 0.06 g, respectively. The corresponding values for the finger pulp were 2.4 mm, 2.2 mm, and 0.01 g, respectively. The static 2-point discrimination and threshold values were superior for the finger pulp, whereas moving 2-point discrimination values at both sites were clinically equivalent.
  
  
  CONCLUSIONS
  Our study suggests that tactile discrimination and threshold levels can be measured over the nail plate and that moving 2-point discrimination values are clinically equivalent to those obtained on the corresponding pulp. This highlights the importance of the nail plate in the sensory function of the fingertip. The normative data from this study may be useful in establishing the impact of nail injury and the contribution of the nail to the overall function of the hand.
  
  
  METHODS
  Diagnostic II.
authors.affiliation: Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Department of Hand and Reconstructive Microsurgery, National University Hospital, Singapore.
authors.forename: Benjamin Zhi Qiang
authors.initials: BZ
authors.lastname: Seah
authors.forename: Clement Chun Ho
authors.initials: CC
authors.lastname: Wu
authors.forename: Sandeep Jacob
authors.initials: SJ
authors.lastname: Sebastin
authors.forename: Amitabha
authors.initials: A
authors.lastname: Lahiri
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008465:Mechanoreceptors / Q000502:physiology; D009262:Nails / Q000502:physiology*; D012016:Reference Values; D012684:Sensory Thresholds / Q000502:physiology*; D055698:Touch Perception; D055815:Young Adult
keywords: Pulp sensation; nail sensation; normative values; tactile sensibility