Geldhof et al 2007. A study on Classroom postures of 8-12 year old children, suggests,

“Prolonged static sitting with a poor posture is common in elementary schoolchildren in Flanders and from a biomechanical point of view, a supplementary spinal load may be assumed. Although the association with back pain at this young age is limited, modifications seem necessary to prevent future back pain. Moreover, it seems that the postural behaviour of young individuals partly depends on components of the class environment, such as school furniture, teaching method, organizational class structures, the pedagogic concept and school management. The current study shows that dynamic sitting is very uncommon in the actual class environment in Flanders. According to this finding and to the literature, it would seem useful to create and evaluate a multi-dimensional primary prevention programme, implementing movement breaks, alterations of class organization and time structures. The development of dynamic sitting habits in school-age children may help to improve sitting habits in adulthood.”