title: Linearity and sex-specificity of impact force prediction during a fall onto the outstretched hand using a single-damper-model.
abstract: OBJECTIVE
  To assess the linearity and sex-specificity of damping coefficients used in a single-damper-model (SDM) when predicting impact forces during the worst-case falling scenario from fall heights up to 25 cm.
  
  
  METHODS
  Using 3-dimensional motion tracking and an integrated force plate, impact forces and impact velocities were assessed from 10 young adults (5 males; 5 females), falling from planted knees onto outstretched arms, from a random order of drop heights: 3, 5, 7, 10, 15, 20, and 25 cm. We assessed the linearity and sex-specificity between impact forces and impact velocities across all fall heights using analysis of variance linearity test and linear regression, respectively. Significance was accepted at P<0.05.
  
  
  RESULTS
  Association between impact forces and impact velocities up to 25 cm was linear (P=0.02). Damping coefficients appeared sex-specific (males: 627 Ns/m, R(2)=0.70; females: 421 Ns/m; R(2)=0.81; sex combined: 532 Ns/m, R(2)=0.61).
  
  
  CONCLUSIONS
  A linear damping coefficient used in the SDM proved valid for predicting impact forces from fall heights up to 25 cm. RESULTS suggested the use of sex-specific damping coefficients when estimating impact force using the SDM and calculating the factor-of-risk for wrist fractures.
authors.affiliation: College of Kinesiology, University of Saskatchewan, Canada.
authors.forename: C E
authors.initials: CE
authors.lastname: Kawalilak
authors.forename: J L
authors.initials: JL
authors.lastname: Lanovaz
authors.forename: J D
authors.initials: JD
authors.lastname: Johnston
authors.forename: S A
authors.initials: SA
authors.lastname: Kontulainen
mesh_terms: D000058:Accidental Falls; D000328:Adult; D001132:Arm; D001696:Biomechanical Phenomena; D005260:Female; D006225:Hand; D006801:Humans; D016014:Linear Models; D008297:Male; D009038:Motion; D011885:Radius Fractures; D015203:Reproducibility of Results; D012727:Sex Characteristics; D055815:Young Adult