Research on Children’s Body Proportions: Determining the Canon of Head Length to Total Body Height on the Example of Children Aged 2 to 15 Years

Proportions and canons of the human body have always been an area of research mainly through art, architecture, or construction, and today, they have a significant application in product design. Research confirms that body height in most cases corresponds to the canon (head–body ratio) of 7.5 to 8 head lengths. This paper investigates the ratio of the head length (HL) to the total body height (BH, stature) of kindergarten and school-aged children, aiming to define the children’s canon inspired by the idea of the harmonic circle theory and the biomechanical model. The data were collected from 1307 children (male 676, female 631) aged 2 to 16 years in the cities of Zagreb (Croatia), Sofia (Bulgaria), and Skopje (North Macedonia). A generalized ESD test (alpha-level 0.10) and Turkey’s 1977 test were used in order to detect outliers in distributions of heights and in the distribution of ratios. Statistical significance was set at 0.05, all p values were two-sided, and the MedCalc statistical tool (version 20.110) was used. The results confirm that canonical changes follow the historical research of artists throughout the centuries, but that they change according to contemporary secular trends in children’s growth and cover HL/BH canons from 5.59 and 5.72 (2-year-old girls and boys) to 7.50 and 7.60 (15-year-old boys and girls) depending on age and gender. HL/BH ratio was significantly higher among female examinees in all age groups where difference was significant (Student’s t test, p < 0.02). In conclusion, such a calculation based on the canon is important for interdisciplinary professions. Creating an anthropological–biomechanical model based on canons, instead of time-consuming measurement, could significantly simplify the long-term collection of anthropometric data used for designing children’s products. Future detailed research is proposed.