The validity of the Caltrac movement sensor for use with preschool children was assessed. Caltrac-derived values for energy expenditure were compared with those derived via laborious coding of direct observation that involved classification of the child’s videotaped activity every other 5 seconds for an hour in the day-care center or on the playground. Both Caltrac and direct observation values were expressed in kilocalories. The subjects were 20 children with a mean age of 35 months. The correlation coefficient for the total of indoor and outdoor activity was r= .62 (p<.01). The separate correlations for indoor and outdoor activity were r=.56 (p<.05) and r=.48 (p<.05), respectively. However, when the children’s weight, height, age, and sex were factored out of both the Caltrac and direct observation scores, the correlations fell to r= .25 (n.s.), r= .47 (p<.05), and r=.16 (n.s.) for the total, indoor, and outdoor activity, respectively. Thus the Caltrac seemed to record indoor activity (mainly walking) more accurately than it recorded the more varied playground movements, casting doubt on its value as a means of measuring physical activity in children 2-3 years of age.
Meke Mukeshi, Bernard Gutin, William Anderson, Patricia Zybert and Charles Basch
Mollie G. DeLozier, Bernard Gutin, Jack Wang, Charles E. Basch, Isobel Contento, Steven Shea, Matilde Irigoyen Patricia Zybert, Jill Rips and Richard Pierson
Anthropometric and bioimpedance regression equations were developed for young children using total body water (TBW) as the criterion. Ninety-six boys and girls, 4-8 years of age, served as subjects. Measures included height, weight, five skinfold thicknesses, three circumferences, total body bioimpedance, and separate bioimpedance measures of the arm, trunk, and leg. Height and weight alone accounted for .70 of the variance in TBW. Adding other measures did not significantly increase the R 2. Standard errors of estimate for TBW were similar to those reported for older individuals (1.39-1.44 1) but may be too large relative to the small size of the subjects for the equations to be acceptable.