[Incidence of short hamstrings and leg muscles at ages 3-17 years]

In 1991, 769 children and adolescents, 98% of the pupils in the various age groups in seven schools and ten kindergartens on Funen, were examined. Seventy-five percent of the boys and 35% of the girls over the age of ten proved to have such short hamstrings that one knee had a extension deficit without violence of > or = 40 degrees when the hip was flexed 90 degrees. More than 10% of the boys over the age of ten had an extension deficit of > or = 60 degrees. Forty-five children had a difference > or = 15 degrees between the two legs. The triceps surae muscles are too short if the corrected foot can only be pressed slowly to the right angle. This was found to be the case for 25-64% of the children from the age of three to 17. Therefore, we must conclude that it is necessary to allow time in kindergarten and school for the children to stretch their muscles a few minutes daily.