title: Quantitation of impact attenuation of different playground surfaces under various environmental conditions using a tri-axial accelerometer.
abstract: OBJECTIVE
  To rank playground surfaces with respect to impact attenuation under various simulated environmental conditions.
  
  
  METHODS
  An accelerometer was dropped from a height of 60 inches onto five different playground surfaces (wood chips, sand, gravel, grass, and commercial rubber mats). Impact attenuation was measured (in G forces) with the above surfaces dry, wet, and frozen.
  
  
  METHODS
  The accelerometer was dropped ten times onto each surface. All surfaces were tested in the wet, dry, and frozen states (saturated with water, then placed at -10 degrees C for 12 hours).
  
  
  RESULTS
  Analysis of variance revealed that wood chips significantly lowered impact forces compared with sand in the wet or dry condition and to grass or synthetic mats in the dry or frozen condition (p < 0.05). Wood chips absorbed the shock of impact significantly more than did gravel in the dry, frozen state.
  
  
  CONCLUSIONS
  Wood chips appear to be the single best playground surface under a variety of environmental conditions when assessed by impact attenuation studies.
authors.affiliation: Division of Emergency Medicine, Saint Louis University Hospital, MO 63110-0250.
authors.forename: L M
authors.initials: LM
authors.lastname: Lewis
authors.forename: R
authors.initials: R
authors.lastname: Naunheim
authors.forename: J
authors.initials: J
authors.lastname: Standeven
authors.forename: K S
authors.initials: KS
authors.lastname: Naunheim
mesh_terms: D000054:Acceleration; D000058:Accidental Falls / Q000517:prevention & control / Q000706:statistics & numerical data*; D000704:Analysis of Variance; D015984:Causality; D002980:Climate; D003257:Consumer Product Safety; D004777:Environment; D005069:Evaluation Studies as Topic; D006112:Gravitation; D006801:Humans; D010988:Play and Playthings; D013499:Surface Properties