Physiological cost index of walking in able-bodied adolescents and adults

Abstract

Fifty-four able-bodied adolescents and 40 adults were assessed in the gait laboratory using an infrared telemetry system. Physiological Cost Index (PCI) of walking ranged from 0.15 beats/metre (b/m) to 0.65 b/m (mean 0.35 b/m, SD 0.09) in adolescents and from 0.2 b/m to 0.55 b/m (mean 0.36 b/m, SD 0.08) in adults. There was no significant difference between median values of PCI in the two study groups. It would appear that the range of PCI values is similar for all age groups. Adult males showed lower PCI than adult females (males 0.31 b/m, SD 0.07 and females 0.4 b/m, SD 0.07; p < 0.001). Quetelet Index of each subject was taken into consideration in order to standardize subjects' body mass and height. There was no correlation between the PCI and the Quetelet Index in either group. Estimation of PCI is a convenient and reliable method to monitor changes in the energy expenditure of walking, is relatively easy and does not require elaborate instrumentation.