Modelling the effects of personal protective clothing properties on the increase of metabolic rate

Many of the PPC garments studied in this thesis are heavy, bulky and made up of multiple layers and stiff fabric as evident from the previous chapters. However it has proved hard to isolate completely the effect of a single garment property on the overall increased energy cost when wearing the actual PPC. An alternative approach to studying the individual contributors to metabolic effects of PPC is by studying them combined. In this chapter, data on a number of PPC properties will be collected and analysed using Pearson’s r and multiple regression, to determine the relative importance of these properties on recorded metabolic rate increases. This technique has been used to study other complex interactions before (Havenith et al. 1995). For this purpose, relevant predictive parameters of the clothing tested in Chapter 3 will be determined (weight distribution, insulation, bulk, stiffness) and the previously observed increases in metabolic rate analysed in relation to these predictors. Attempts will be made to use simple and non-destructive methods to determine the parameters, in order that tests could be repeated by others and would be usable in the workplace.