Abstract des Autors

The purpose of this study was to find out whether the sex and puberty-related differences in walking and running economy, defined as the oxygen uptake relative to body mass (VO2/BM) at submaximal speeds, can be explained by differences in co-ordination patterns. In 10 prepubertal boys and girls (mean age: 10.2+/-0.5(SD) yrs) and 11 postpubertal boys and girls (mean age: 15.4+/-0.4 yrs), oxygen uptake relative to body mass (VO2/BM) was measured during walking and running on a treadmill at the speeds of 4, 6, 8 and 10 km/h. Movements of the arms and legs were recorded with accelerometer to estimate the co-ordination pattern. Six mean relative phases were calculated from the raw accelerometers data. The standard deviations of these relative phases were computed to illustrate stability of the co-ordination pattern. More efficient economy of locomotion and more stable pattern of co-ordination was found in young girls than in boys of matching age. Better stability of co-ordination in girls over all the speeds partly explains the sex difference in walking and running economy within the age range examined. Postpubertals had better than prepubertals economy of locomotion and more stable pattern of co-ordination. It is concluded that efficient walking and running economy can be, at least partly, explained by better stability of arms and legs. Verf.-Referat