Effect of training on the use of weight-bearing orthoses.

Weight-bearing orthoses have been disigned with the primary goal of reducing or eliminating weight bearing in skeletal structures. In evaluating various designs and adjustments of these orthoses, we found that the training of the subject in the use of his orthosis was one of the most significant factors in controlling weight bearing. Subjects fitted with instrumented ischial weight-bearing and patellar-tendon-bearing orthoses walked over a force plate which measured forces imparted to the floor. The force data from the orthoses and force plate were computer-processed with single frame, multiple exposure photographic data to provide plots of axial loading in the orthosis and total axial loading imparted to the floor during the duration of the stance phase. The difference between these two forces represents the load carried by the skeletal system. Measurements were made first with subjects who had no specific instructions about the use of their orthoses. The subjects were then instructed how to use their orthoses more efficiently. In all cases, the effect of training produced a 30 to 50 percent increase in loading borne through the orthosis.