Chronological changes of the axis of the lower extremities in 96 children from 3 to 5 years old were studied. Distance between medial condyles or medial malleoli and Carter's index of joint laxity were physically examined and the following angles were roentgenographically examined; (1) femoro-tibial angle (FTA), (2) femora-vary (PV), (3) tibia-vara (TV), (4) proximal tibial metaphysealdiaphyseal angle (TMDA), and (5) distal tibial metaphyseal diaphyseal angle (TMDAD).
Results were as follows; 1, FTA was the most useful among those angles for evaluation of the chronological changes of the axis of the lower extremities. 2, At the age of 3 years FTA was the smallest. In other words, the knees showed marked valgus position. From 3 to 5 years old, FTA decreased with growth. The valgus position of the knee is corrected by itself gradually. 3, The change at the proximal metaphysis of the tibia (TMDA) was found to influence most closely on the changes in FTA.