Study aim: Body posture changes depend on numerous factors. The purpose of this study was to assess the changes in posture in the sagittal plane of children aged 7–12 years.

Material and methods: Postural changes were determined by assessing the postural parameters in the sagittal plane. The measurements were recorded in children attending selected primary schools. In total, 562 subjects were included in the study, including 278 boys and 284 girls. The body posture was assessed photogrammetrically based on the moiré effect, whereby 5 postural parameters were integrated within the measurement methodology.

Results: The results indicated a naturalistic tendency in postural development – the postural parameters changed with age in a dynamic fashion; and the postural measurements for boys and girls differed in terms of their range.

Conclusions: The study findings can be used for the accurate mapping of normal postural development and, inter alia, for the detection and diagnosis of an emerging abnormal posture. Importantly, a correct postural assessment algorithm for children should include the subject’s age and sex.