Citation

Nagata H. Safety Sci. 1995; 21(1): 37-49.

Copyright

(Copyright © 1995, Elsevier Publishing)

DOI

unavailable

PMID

unavailable

Abstract

As walkers perceive more difficulty while descending stairs, they are likely to experience mis-steps or to trip. In this paper the perceived difficulty while descending stairs with various tread/rise combinations is evaluated using sensory tests. An index to design tread depth and rise height is found from a multiple regression analysis of experimental results.Ten young males (average age 21.0), ten young females (average age 19.7) and ten elderly males (average age 71.2) assessed 42 tread/rise combinations while descending stairs. The female group wore 4 different types of footwear differing in heel height. As a result, dimensions of tread and rise with less difficulty in descending stairs were shown to exist in certain combinations, around 29-30 cm tread and 18 cm rise for lower heeled footwear, and around 30 cm tread and 15.5 cm rise for higher heeled footwear. Perceived difficulty increases as the measurements deviate from these combinations. The results of the subjects' evaluations are quantified using the psychometric method of successive categories, which is based on the assumption that the frequency distribution of all evaluations for each tread/rise combination is normal. From a multiple regression analysis of quantified results and considering the potential risk of high heeled footwear, a rational index to design tread depth and rise height is presented in this paper.