Technical Information

sd of final height predictionsd of final height predictionAutomatized analysis of growth and developmental tempo
(willi-will-wachsen)

Child growth is characterised by increases in height, and increases in maturational status. Functional data analysis provides a tool to separate these two sources of variation (registration) and differentiates between the variation in maturational tempo (temporal, or “phase” variation) and the variation in height (amplitude variation). We extended this concept by combining Principal Component Analysis (PCA) and Maximum Likelihood Principle. The combination of PCA and Maximum Likelihood Principle provides a new, powerful and automatic tool for growth modelling that includes estimates of future growth, adult stature and developmental tempo. Preliminary results indicate that this approach can be used for automatised screening purposes. The website www.willi-will-wachsen.com may be used for automatic growth modelling.

Knemometer, Mini-Knemometer
mini-knemometermini-knemometerknemometerknemometerIn 1983, an attractive technique was developed for accurate non-invasive determinations of the lower leg length (knemometry). This device is easier to handle, it has a measurement error between 0.09 mm (Valk et al. 1983) and 0.16 mm (Hermanussen et al. 1988a), and is observer independent (Wales and Milner 1987). Initially, intervals of three weeks were recommended for short-term growth measurements, but it soon became obvious that intervals of one week were technically feasible, and provided evidence for non-linear progress of growth at short-term (Hermanussen et al. 1988b, Wit et al. 1987). Besides the original device, similar techniques for lower leg measurements were inaugurated, a modified Danish knemometer by Michaelsen et al. (1991), a Polish knemometer (Hulanicka et al. 1999), a “knee height measuring device” by Cronk et al. (1989), a portable knemometer by Davies et al. (1996) for measuring sitting individuals, a miniaturised portable knemometer (1.5 kg) for field work (Hermanussen, unpublished), and an Italian device (Benso, personal communication 1992). Mikro-knemometry is available for lower leg length measurements in rodents (Hermanussen et al. 1992, Hermanussen et al. 1995), and a particularly small version (mini-knemometer) for the measurement of infants, or neonates and premature infants within their incubators (Hermanussen, Seele 1997, Kaempf et al. 1998). The latter devices operate with a precision that reduces the amount of variance due to measurement error, to five percent of the total variance of 24 hour measurement series, and thus visualise length changes within periods of less than one day.

daily lower leg growthdaily lower leg growth

  • Cronk C.E., Stallings V.A., Spender Q.W., Ross J.L., and Widdoes H.D., 1989, Measurement of short term growth with a new knee height measuring device (KHMD). American Journal of Human Biology, 1, 421-428.
  • Davies H.A., Pickering M., and Wales J.K.H., 1996, A portable knemometer: a technique for assessment of short-term growth. Annals of Human Biology, 23, 149-157.
  • Hermanussen M., and Seele K., 1997, Mini-knemometry: an accurate technique for lower leg length measurements in early childhood. Annals of Human Biology, 24, 307-313.
  • Hermanussen M., Geiger-Benoit K., Burmeister J., and Sippell W.G., 1988, Knemometry in childhood: accuracy and standardization of a new technique of lower leg length measurement. Annals of Human Biology, 15, 1-16.
  • Hermanussen M., Geiger-Benoit K., Burmeister J., Sippell W.G., 1988, Periodical changes of short term growth velocity ("mini growth spurts") in human growth. Ann Hum Biol 15, 103-109.
  • Hermanussen M., Bugiel S., Aronson S., and Moell C., 1992, A non-invasive technique for the accurate measurement of leg length in animals. Growth, Development & Aging, 56, 129-140.
  • Hermanussen M., Rol de Lama M., Burmeister J., and Fernandez-Tresguerres J.A., 1995, Mikro-knemometry: an accurate technique of growth measurement in rats. Physiology and Behavior, 58, 347-352.
  • Hulanicka B., Gronkiewicz L., and Koziel S., 1999, Wzrastanie dzieci badanie knemometryczne. Monografie. Zakladu Antropologii Polskiej Akademii Nauk. Wroclaw.
  • Kaempf D.E., Pflüger M.S., Thiele A.M., Hermanussen M., and Linderkamp O., 1998, Influence of nutrition on growth in premature infants: assessment by knemometry. Annals of Human Biology, 25, 127-136.
  • Michaelsen K.F., Skov L., Badsberg J.H., and Jorgensen M., 1991, Short-term measurement of linear growth in preterm infants: validation of a hand-held knemometer. Pediatric Research, 30, 464-468.
  • Valk I.M., Langhout Chabloz A.M.E., Smals A.G.H., Kloppenborg P.W.C., Cassorla F.G., and Schutte E.A.S.T., 1983, Accurate measurement of the lower leg length and the ulnar length and its application in short term growth measurements. Growth, 47, 53-66.
  • Wales J.K.H., and Milner R.D.G., 1987, Knemometry in the assessment of linear growth. Archives of Disease in Childhood, 62, 166-171.
  • Wit J.M., van Kalsbeek E.J,. von Wijk-Hoek J.M., and Leppink G.J., 1987, Assessment of the usefulness of weekly knemometric measurements in growth studies. Acta Paediatrica Scandinavica, 76, 974-980.

Synthetic growth charts(Hermanussen, Cole 2003)(Hermanussen, Cole 2003)

National standards for growth in height and length belong to the traditional inventory of the paediatric practice. Yet, national standards are world-wide only available for few major ethnic groups. Most children and adolescents from the smaller countries, and many ethnic minorities, particularly the children from developing countries, must still be referred to "international" usually US-based growth references. In view of this dilemma, we introduced a method to generate synthetic reference standards for height, weight and BMI (Hermanussen and Burmeister 1999). Snythetic references are based on data obtained at certain design age groups (at birth, and at the ages of 2,6,14, and 18 years in males; respectively at birth, and at the ages of 2,6,14, and 18 years in females) and generate age-specific linear regression coefficients. These coeffients are used to calculate mean values, standard deviations and centiles for height, weight and BMI of all age groups from birth to maturity. Synthetic growth charts are used in several countries, and have recently been generated and published for German born Turkish children and adolescents (Redlefsen et al. 2007).

  • Hermanussen M, Burmeister J (1999) Synthetic growth charts. Acta Paediatr Scand 88:809-14.
  • Redlefsen T, Commentz J, Meigen C, Hermanussen M (2007) Referenz values for height, weight and body mass index of German born Turkish children. Anthrop Anz 65:263-74.