Document Type



Right and left grip strength and three measures of motor performance (35 yard dash, standing long jump, ball throw for distance) were measured in a cross- sectional sample of primary school children, 6 through 15 years of age, from a rural Zapotec-speaking community in the Valley of Oaxaca, Mexico. Sample sizes per task varied between 332 and 364 children. Absolute strength and motor performance of the Zapotec children are significantly below those of better nourished Philadelphia school children. When corrected for body size differences, i.e., per unit height and weight, the rural Zapotec children perform commensurately with their smaller body size in the dash and jump at the early ages, but less than expected for their size at the older ages. Strength per unit size is slightly, but consistently less in the Zapotec children, while throwing distance per unit size is consistently greater in the Zapotec children. The pattern of zero order and second order partial correlations between performance and age, height and weight is similar to that for samples of well-nourished children. After controlling for age, height and weight, other anthropometric variables contribute little to explaining variation in performance of the Zapotec children. Given the reduced absolute levels of strength and performance in the Zapotec children, and generally reduced levels after controlling for size variation (except in the throw), these observations do not support the postulate of superior functional efficiency in association with reduced body size in undernourished populations