Content area
Full Text
Linear growth is a cardinal index of physical development through childhood and adolescence. Accurate and reproducible measurement of height is thus essential in longitudinal follow-up of individual children or populations, as well as in cross-sectional group studies.1 The reliable determination of height velocity, based on serial measurements in an individual over time, is similarly dependent upon such accuracy and precision. It is important since it is the basis for eligibility for and response to various growth-promoting therapies.2 A range of issues contributing to the variance of measurements has long preoccupied those concerned with linear growth. These issues include the accuracy and precision (reproducibility) of measuring devices, the reliability of the measuring skills of the observer, and variation in the individual being measured. A key contributor to this last issue has been the well-recognised diurnal variation in height; a person is tallest on rising in the morning, and shrinks by 05-15 cm during the day (as the spine becomes compressed, and the spinal muscles tire).3-5 This pattern, first reported in 1726,(6) means that the time of day when a person is measured also becomes important in serial height assessment. The use, by Whitehouse and colleagues, of gentle stretching by upward pressure on the mastoid during height...