ESTIMATION OF DEFORMATION IN A WALKING ORTHOSIS FOR PARAPLEGIC PATIENTS

Although good results have already been achieved in reciprocal walking for paraplegic patients using mechanical orthoses (e.g. ORLAU ParaWal ker), improvements in lateral stiffness of walking devices could incre ase significantly the efficiency of ambulation. For this reason a meth od for monitoring the structural properties of an orthosis during loco motion has been studied. A motion analysis system (ELITE system) able to detect automatically and accurately the positions of small retroref lective markers in a television field was used. Starting from marker p ositions, the angular variations between adjacent structural segments in the orthosis were computed and the areas in which maximum deformati ons occurred were identified. Experiments were performed on two parapl egic patients using their ORLAU ParaWalker orthosis and two different kinds of movements were analysed: lateral tilting and walking. The res ults show that this approach is able to detect the small deformations occurring in the orthotic structure and therefore to provide valuable information for orthotic design optimization.