CHILDREN DO NOT GROW CONTINUOUSLY BUT IN SPURTS

The description of the human growth pattern is limited largely to the traditional vocabulary of ''linear growth rates,'' i.e., height or len gth increments divided by certain time intervals such as months or yea rs. These studies have been performed using conventional techniques of body length or stature measurement with a technical error of approxim ately 1.5 mm. During the last 10 years, measurements of lower leg leng th (knemometry) have been performed with a significantly lower technic al error (0.09-0.16 mm). Repeated determinations of lower leg length a t short intervals are now feasible, and evidence indicates that 'short term growth'' is a phenomenon that includes both length increment and decrement. At measurement intervals of exactly 1 week, growth appears periodic showing marked spurts that alternate with intervals of decre ased growth velocity with a peak-to-peak distance of 30-55 days (mini growth spurts). These spurts have significant clinical importance and can be used as predictive criteria for successful growth promotion in growth hormone therapy of short stature. Lower leg length measurements at 24-hour intervals provide evidence for the existence of circasepta n periodicity. (C) 1993 Wiley-Liss, Inc.