title: Factors affecting extension ladder angular positioning.
abstract: OBJECTIVE
  The study objectives were to identify factors affecting extension ladders' angular positioning and evaluate the effectiveness of two anthropometric positioning methods.
  
  
  BACKGROUND
  A leading cause for extension ladder fall incidents is a slide-out event, usually related to suboptimal ladder inclination. An improved ladder positioning method or procedure could reduce the risk of ladder stability failure and the related fall injury.
  
  
  METHODS
  Participants in the study were 20 experienced and 20 inexperienced ladder users. A series of ladder positioning tests was performed in a laboratory environment with 4.88-m (16-ft) and 7.32-m (24-ft) ladders in extended and retracted positions. The setup methods included a no-instruction condition and two anthropometric approaches: the American National Standards Institute A14 and "fireman" methods. Performance measures included positioning angle and time.
  
  
  RESULTS
  The results indicated that ladder setup method and ladder effective length, defined by size and extended state, affected ladder positioning angle. On average, both anthropometric methods were effective in improving extension ladder positioning; however, they required 50% more time than did the no-instruction condition and had a 9.5% probability of setting the ladder at a less-than-70 degrees angle. Shorter ladders were consistently positioned at shallower angles.
  
  
  CONCLUSIONS
  Anthropometric methods may lead to safer ladder positioning than does no instruction when accurately and correctly performed. Workers tended to underperform as compared with their theoretical anthropometric estimates. Specific training or use of an assistive device may be needed to improve ladder users' performance.
  
  
  CONCLUSIONS
  The results provide practical insights for employers and workers to correctly set up extension ladders.
authors: Protective Technology Branch, Division of Safety Research, NIOSH, 1095 Willowdale Rd., MS G-800, Morgantown, WV 26505, USA. psimeonov@cdc.gov
authors: Peter
authors: P
authors: Simeonov
authors: Hongwei
authors: H
authors: Hsiao
authors: In-Ju
authors: IJ
authors: Kim
authors: John R
authors: JR
authors: Powers
authors: Tsui-Ying
authors: TY
authors: Kau
mesh_terms: D000058:Accidental Falls / Q000517:prevention & control*; D000328:Adult; D000886:Anthropometry; D003252:Construction Materials; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012449:Safety; D013647:Task Performance and Analysis