Measurement of the Width of Ischial Tuberosity for Indian Male Motorcycle Users

Abstract

The Ischial tuberosity or sitting bones bear the weight of the body when sitting. The width of the ischial tuberosity is, therefore, an important consideration when designing seats, especially narrow seats like bicycle and motorcycle. The aim of this study is to measure the width of ischial tuberosity for Indian male motorcycle users. The width of ischial tuberosity is measured using seat interface pressure map. Ischial tuberosity being a bony projection with very little tissue and muscle covering while sitting are clearly reflected as high pressure areas on a pressure map. A total of 63 male volunteers participated in this study. Seat pressure measurements are carried out for each subject while seated on a hard surface. The resulting data is analysed to measure the width of ischial tuberosity and its general statistical distribution. The results show that the mean width of ischial tuberosity is 111.8 mm with a standard deviation of 9.3 mm. The 5th and 95th percentile values are 97.3 and 127.8 mm, respectively. The dimension of ischial tuberosity can be the basis for defining the minimum width of seat required for narrow seats like bicycles and motorcycles.