title: Mechanography in childhood: references for grip force, multiple one-leg hopping force and whole body stiffness.
abstract: OBJECTIVE
  We sought to study and procure reference values for weight-related maximum isometric grip force (MIGF), maximum voluntary force in relation to body weight (Fmvrel) and peak whole body stiffness (pKwb) in multiple one-legged hopping (m1LH) in childhood.
  
  
  METHODS
  We examined 868 children and adolescents (436 female) aged 3 to 19 yrs. Weight related results are reported as multiples of earth's gravity (g).
  
  
  RESULTS
  MIFG and Fmv(m1LH) are highly linearly correlated with body weight. After adjustment for weight, mean Fmvrel(m1LH) increases from the age of 3 to 6 yrs, then remains at 3.33 g (SD 0.31 g) between 6 and 19 yrs, independent of age and gender. The difference between legs decreases from 10% at 3 yrs to a constant 5.5% after the age of 7 yrs. Weight-adjusted MIGF also increases steeply from 3 to 6 yrs, then shows a further linear, less steep increase - in males through to age 19 yrs while females show a near-standstill after the age of 12 yrs. pKwb(m1LH) increases from the age of 7 yrs.
  
  
  CONCLUSIONS
  This data from normal children from a healthy Caucasian population provide a reference for tests of motor function.
authors.affiliation: University Children's Hospital Tübingen, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Lang
authors.forename: P
authors.initials: P
authors.lastname: Busche
authors.forename: N
authors.initials: N
authors.lastname: Rakhimi
authors.forename: R
authors.initials: R
authors.lastname: Rawer
authors.forename: D D
authors.initials: DD
authors.lastname: Martin
mesh_terms: D000293:Adolescent; D001696:Biomechanical Phenomena; D001835:Body Weight / Q000502:physiology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006112:Gravitation; D018737:Hand Strength / Q000502:physiology*; D006257:Head / Q000033:anatomy & histology; D006801:Humans; D007537:Isometric Contraction; D007866:Leg / Q000033:anatomy & histology / Q000502:physiology*; D008297:Male; D009068:Movement / Q000502:physiology; D005082:Physical Exertion / Q000502:physiology*; D012015:Reference Standards; D015203:Reproducibility of Results; D012727:Sex Characteristics; D044465:White People; D055815:Young Adult