title: Effect of boot weight and sole flexibility on gait and physiological responses of firefighters in stepping over obstacles.
abstract: OBJECTIVE
  The authors investigated the effect of boot weight and sole flexibility on spatiotemporal gait characteristics and physiological responses of firefighters in negotiating obstacles.
  
  
  BACKGROUND
  Falls and overexertion are the leading causes of fire ground injuries and fatalities among firefighters. There have been few in-depth studies conducted to evaluate the risk factors of falls and overexertion associated with firefighter boots.
  
  
  METHODS
  For the study, 13 female and 14 male firefighters, while wearing full turnout clothing and randomly assigned boots, walked for 5 min while stepping over obstacles. The independent variables included boot weight, sole flexibility, gender, and task duration. Spatiotemporal measures of foot trajectories and toe clearance were determined. Minute ventilation, oxygen consumption, carbon dioxide production, and heart rate were measured.
  
  
  RESULTS
  Increased boot weight was found to significantly reduce trailing toe clearance when crossing the 30-cm obstacle. Significant increases in lateral displacement of the foot were found near the end of the 5-min walk compared with the beginning of the task Increased boot weight significantly increased oxygen consumption. There were significant decreases in oxygen consumption for more flexible soles.
  
  
  CONCLUSIONS
  Firefighters were more likely to trip over obstacles when wearing heavier boots and after walking for a period of time. Boot weight affected metabolic variables (5% to 11% increases per 1-kg increase in boot weight), which were mitigated by sole flexibility (5% to 7% decrease for more flexible soles).
  
  
  CONCLUSIONS
  This study provides useful information for firefighters and boot manufacturers in boot selection and design for reducing falls and overexertion.
authors: Division of Safety Research, National Institute for Occupational Safety and Health, 1095 Willowdale Rd. G800, Morgantown, WV 26505, USA. schiou@cdc.gov
authors: Sharon S
authors: SS
authors: Chiou
authors: Nina
authors: N
authors: Turner
authors: Joyce
authors: J
authors: Zwiener
authors: Darlene L
authors: DL
authors: Weaver
authors: William E
authors: WE
authors: Haskell
mesh_terms: D000062:Accidents, Occupational / Q000517:prevention & control; D000328:Adult; D018592:Cross-Over Studies; D004867:Equipment Design; D005260:Female; D061388:Firefighters; D005684:Gait; D006801:Humans; D008297:Male; D010101:Oxygen Consumption; D011481:Protective Clothing; D012775:Shoes; D013647:Task Performance and Analysis; D055815:Young Adult