Seat Height, which is the starting point for the design of class- room furniture and also the measure used for prescription of a set size (Garcı´a-Acosta and Lange-Morales, 2007; Molenbroek et al., 2003), was appropriate for Popliteal Height in only 14% of the students from school A, 28% from school B and 14% from School C (Fig. 3).