title: Variability and distribution of muscle strength and its determinants in humans.
abstract: BACKGROUND
  Inter-individual variability in measurements of muscle strength and its determinants was identified to: (1) produce a normative data set describing the normal range and (2) determine whether some measurements are more informative than others when evaluating inter-individual differences.
  
  
  METHODS
  Functional and morphological characteristics of the vastus lateralis were measured in 73 healthy, untrained adult men.
  
  
  RESULTS
  Inter-individual variability (coefficient of variation) was greater for isometric maximal voluntary contraction (MVC) torque (18.9%) compared with fascicle force (14.6%; P=0.025) and physiological cross-sectional area (PCSA; 17.2%) compared with anatomical cross-sectional area (ACSA, 13.0%; P<0.0005). The relationship between ACSA and isometric MVC torque (r(2)  =0.56) was weaker than that between PCSA and fascicle force (r(2)  =0.68).
  
  
  CONCLUSIONS
  These results provide a normative data set on inter-individual variability in a variety of muscle strength-related measurements and illustrate the benefit of using more stringent measures of muscle properties. Muscle Nerve 49: 879-886, 2014.
authors.affiliation: Centre for Genomic Research into Exercise, Performance and Health, Institute for Performance Research, Manchester Metropolitan University, Crewe Green Road, Crewe, Cheshire, CW1 5DU.
authors.forename: Georgina K
authors.initials: GK
authors.lastname: Stebbings
authors.forename: Christopher I
authors.initials: CI
authors.lastname: Morse
authors.forename: Alun G
authors.initials: AG
authors.lastname: Williams
authors.forename: Stephen H
authors.initials: SH
authors.lastname: Day
mesh_terms: D006801:Humans; D007537:Isometric Contraction / Q000502:physiology; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D053580:Muscle Strength / Q000502:physiology*; D053581:Muscle Strength Dynamometer; D018482:Muscle, Skeletal / Q000502:physiology*; D012016:Reference Values; D055815:Young Adult
keywords: force; inter-individual variation; muscle size; muscle strength; vastus lateralis