Intradaily variation of the human lower leg length and short term growth--a longitudinal study in fourteen children.

In order to detect the intradaily variation of the lower leg length in fourteen children the right lower leg length was determined using a non-invasive lower leg length measuring device at three set times of each day during a study period of three weeks. The mean standard error of the determinations amounted to 0.04 mm. As far as the whole group was concerned the lower leg length decreased significantly during the time interval from 8.00 hours to 12.00 hours. (Friedman's related samples test, p less than 0.01). The decrement amounted to 0.6 mm. During the rest of the day the changes in the lower leg length were not significant. A consistent decrement of the lower leg length during the day in combination with a total growth of 1.08 mm. during the three week study period suggested that growth in length of the human lower leg occurs during the night.