KNEMOMETRY AND THE ASSESSMENT OF GROWTH IN PREMATURE BABIES

The characteristics of a knemometer designed for accurate lower leg me asurement in babies were assessed. Repeated measurement of a 100 mm Pe rspex rod gave a mean length of 99.993 mm and a mean SD of 0.058. When used to measure leg length, technical error of the measurement techni que was 0.31 with a mean leg length of 98.49 mm (coefficient of variat ion 0.31%). Leg lengths measured at birth in 324 babies from 23 to 42 weeks' gestation gave an estimated in utero leg length velocity of 0.4 3 mm/day (95% confidence interval 0.41 to 0.45). Assessment of interob server variation showed poor agreement in absolute values of leg lengt h, although similar estimates of leg length velocity could be obtained . The neonatal knemometer allows measurements to be made in situations where conventional growth measurements are not possible. It is believ ed that knemometry has an important role in accurate evaluation of fac tors that can influence short term bone growth.