Fig. 1. Measured axes and angles in the pitch plane. Head axis was a line passing through the external auditory meatus and the apex of the prognathous mouth. Trunk axis was a line passing through the hip and shoulder joints. Head angle relative to space () and trunk angle relative to space (ß) were measured in reference to earth horizontal. Head-to-trunk angle () was calculated from the head-to-space and trunk-to-space angles.