Assessment of the usefulness of weekly knemometric measurements in growth studies.
In 31 healthy children the variability of lower leg length growth over 12 weekly measuring sessions, each consisting of 6 measurements, was assessed with a knemometer. The average SD of 6 measurements was 0.12 mm. In many cases not only a rising trend, but also a zig-zag pattern was observed. The linear regression was not significant (p greater than 0.05) in 1 child. The average (+/- SD) lower leg length velocity (LV) was 0.36 +/- 0.14 mm/week, and the average statural growth velocity 1.27 +/- 0.54 mm/week. The median ratio was 3.3. The range of both velocities was greater than the range of annual height velocities. When LV over the first 6 weeks was compared with LV over the next 6 weeks, a significant difference was found in 5 children. If the effect of growth-promoting or -inhibiting drugs were to be analyzed over such periods, a difference of 0.37 mm/week over two 6-week-periods would be necessary for significance at a 5% level. This would be equivalent with a statural growth response of at least 6.3 cm/year. In conclusion, short-term knemometric growth response cannot be used as a reliable predictor of long-term statural growth response.
Department of Paediatrics, University Hospital for Children and Youth Het Wilhelmina Kinderziekenhuis, Ultrecht, The Netherlands.
J M
JM
Wit
E J
EJ
van Kalsbeek
J M
JM
van Wijk-Hoek
G J
GJ
Leppink
D000886:Anthropometry / Q000379:methods*; D002648:Child; D005260:Female; D006801:Humans; D007866:Leg / Q000254:growth & development*; D008297:Male; D012016:Reference Values; D013997:Time Factors