title: Influence of wet surfaces and fall height on pediatric injury risk in feet-first freefalls as predicted using a test dummy.
abstract: BACKGROUND
  Falls are a major cause of morbidity and mortality in children, but are also reported falsely in child abuse. Therefore, it is of interest to understand those factors which may lead to a higher likelihood of injury in a feet-first freefall.
  
  
  METHODS
  We used laboratory freefall experiments and a 3-year-old Hybrid III anthropomorphic test dummy (ATD) to assess head and femur injury risk. Wet and dry linoleum impact surfaces were used from three fall heights: 22, 35 and 47 in.
  
  
  RESULTS
  For a given fall height, dry surfaces were associated with higher head injury criteria (HIC) values than wet surfaces. Changes in fall height 22-47 in. did not significantly affect HIC values for falls onto either surface. Generally, compressive and bending femur loading increased significantly for wet as compared to dry linoleum.
  
  
  CONCLUSIONS
  In simulated feet first freefall experiments up to 47 in. using a 3-year-old test dummy, a low risk of contact type head injury and femur fracture was found. However, both fall height and surface conditions influenced femur loading and head injury measures. Future efforts should explore the risk of head injury associated with angular acceleration in freefalls.
authors.affiliation: Department of Mechanical Engineering, University of Louisville, 110 Instructional Building, Louisville, KY 40292, USA. bc.deemer@louisville.edu
authors.forename: Ernest
authors.initials: E
authors.lastname: Deemer
authors.forename: Gina
authors.initials: G
authors.lastname: Bertocci
authors.forename: Mary Clyde
authors.initials: MC
authors.lastname: Pierce
authors.forename: Fernando
authors.initials: F
authors.lastname: Aguel
authors.forename: Janine
authors.initials: J
authors.lastname: Janosky
authors.forename: Ev
authors.initials: E
authors.lastname: Vogeley
mesh_terms: D000054:Acceleration; D000058:Accidental Falls / Q000517:prevention & control*; D000531:Altitude; D002649:Child Abuse / Q000175:diagnosis; D002675:Child, Preschool; D003198:Computer Simulation; D006259:Craniocerebral Trauma / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology* / Q000517:prevention & control; D003937:Diagnosis, Differential; D005264:Femoral Fractures / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology* / Q000517:prevention & control; D006801:Humans; D008348:Manikins; D008954:Models, Biological; D010812:Physical Stimulation / Q000009:adverse effects; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D013314:Stress, Mechanical; D013499:Surface Properties