title: Intermuscular relationship of human muscle fiber type proportions: slow leg muscles predict slow neck muscles.
abstract: BACKGROUND
  Our aim in this study was to examine whether the muscle fiber type proportions in different muscles from the same individual are interrelated.
  
  
  METHODS
  Samples were excised from five skeletal muscles in each of 12 human autopsy cases, and the fiber type proportions were determined by immunohistochemistry. We further examined the intermuscular relationship in fiber type proportion by reanalyzing three previously published data sets involving other muscles.
  
  
  RESULTS
  Subjects demonstrated a predominantly high or low proportion of type 1 fibers in all examined muscles, and the overall difference between individuals was statistically significant (P < 0.001). Accordingly, the type 1 fiber proportions in most muscles were positively correlated (median r = 0.42, range -0.03-0.80). Similar results were also obtained from the three reanalyzed data sets.
  
  
  CONCLUSIONS
  We suggest the existence of an across-muscle phenotype with respect to fiber type proportions; some individuals display generally faster muscles and some individuals slower muscles when compared with others.
authors.affiliation: Department of Health Sciences, University of Oslo, P.O. Box 1089 Blindern, N-0317 Oslo, Norway. harald.vikne@medisin.uio.no.
authors.forename: Harald
authors.initials: H
authors.lastname: Vikne
authors.forename: Kristian
authors.initials: K
authors.lastname: Gundersen
authors.forename: Knut
authors.initials: K
authors.lastname: Liestøl
authors.forename: Jan
authors.initials: J
authors.lastname: Maelen
authors.forename: Nina
authors.initials: N
authors.lastname: Vøllestad
mesh_terms: D000328:Adult; D000368:Aged; D019412:Anatomy, Cross-Sectional; D001344:Autopsy; D002452:Cell Count; D048429:Cell Size; D004396:Coloring Agents; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D007866:Leg / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction / Q000502:physiology; D018656:Muscle Fibers, Fast-Twitch / Q000502:physiology*; D018657:Muscle Fibers, Slow-Twitch / Q000502:physiology*; D018482:Muscle, Skeletal / Q000166:cytology / Q000502:physiology; D009334:Neck Muscles / Q000166:cytology* / Q000502:physiology*
chemical_list: D004396:Coloring Agents