Measurement of contact pressure distributions between soles and floor surface using a photoelastic technique and its clinical significance. (Mechanical analysis of standing posture in children with down syndrome).

A photoelastic method was used for a new device to measure contact pressure distribution between soles and the floor surface. The size of a first fringe was linearly correlated with weight loaded upon the point. Its error ranges were within 3%. When 17 individuals with Down syndrome (ages 1-15 years) and 27 controls (ages 1-50 years) were analysed by this method, it was revealed that, in the former, the number of points with a first fringe was increased and, in the latter, an average loading weight for each point with a first fringe was increased. From the patterns of contact pressure distribution of soles, the center of gravity for each sole and that of a whole body were determined. In the Down syndrome group, the position was shifted forward at 50% the length of the sole from the ankle; meanwhile, it was only 35% in the control.