Maximal voluntary isometric strength in Danish adolescents 16-19 years of age.

The force in maximal voluntary isometric contraction of elbow flexors, knee extensors, trunk flexors, and trunk extensors was measured in a representative sample of Danish school children 16-19 years of age (128 boys and 165 girls). The 16 year old boys were 177.8 cm in height, with a mean increase of 1.4 cm per year up to 19 years, and they weighed 66.0 kg, with a mean increase of 1.8 kg per year up to age 19. The girls were 168.0 cm in height with no increase up to age 19, and their mean weight was 59.6 kg, which increased by 1.8 kg per year up to age 19 (p greater than 0.05). The strength in the four muscle groups for boys a girls respectively was 281 N and 182 N for elbow flexors, 574 N and 419 N for knee extensors, 601 N and 404 N for trunk flexors and 664 N and 499 N for trunk extensors. An increase in strength in the elbow and trunk flexors and a decrease in strength in the trunk extensors in relation to values obtained in 1956 was seen, and a difference in strength per kg lean body mass between the boys and the girls was also observed. The estimated strength per unit cross-sectional area of muscle was 38 N X cm-2 in both boys and girls.