Converting Tanner-Whitehouse reference tricep and subscapular skinfold measurements to standard deviation scores

The use of conventional standard deviation (SD) scores is inappropriate when data are not normally distributed, as is the case with the tricep and subscapular skinfolds. However, it is now possible to summarize centile data in three age-specific parameters (called L, M and S) and by the appropriate use of these parameters, SD scores for skinfold measurements can be calculated that take into account skewness in the centile data. The L, M and S parameters for the tricep and subscapular skinfolds from age 1 to 19 years [J. M. Tanner & R. H. Whitehouse (1975) Arch. Dis. Childh. 50, 142-145] are presented and the equation for the calculation of SD scores described.