Height velocity measurements (Fig. 14.9) are converted into annual rates of growth by dividing the increment by the lapse of time. Such measurements are compared with centiles as before but, whereas a third centile position on a height distance chart may be, and probably is, normal, a velocity that is persistently on the third centile leads to progressive loss of height compared with children of the same age. The growth velocity of a given child must oscillate about the fiftieth percentile to maintain growth along a centile chart on a distance chart. Visual inspection on a distance chart is not a substitute for calculating the height velocity and plotting it on a centile chart.
