A simple idea for reducing the cost and weight of plaster-cast orthoses *

ObjectiveTo reduce the cost and weight of plaster molded orthosis (increasing patient comfort), keeping the same resistance.Methods22 plaster orthosis were analysed, 11 with conventional shape and 11 with pyramidal shape. It was compared, in theory (mathematcally) and practice, the change of weight (and consequently cost) and flexion resistance between conventional shape and pyramidal shape.ResultsTheorical analysis: weight and cost decrease of 26.7%-38.9%, according to the layers disposition of the cast. Laboratorial analysis: cast's weight decrease of 34.5% (p = 0.000005) and resistance increase of 26.7% (p = 0.03).Conclusionplaster molded orthosis made in a pyramidal shape, have a statistically significant decrease of weight (and consequently cost) and statistically significant increase of resistance if compared with traditional shape.