1. Universidade Federal do Espirito Santo,Department of Mechanical Engineering,ES,Brazil,29075-910
2. Harvard Medical School,Spaulding Rehabilitation Hospital,Department of Physical Medicine & Rehabilitation,Charlestown,MA,02129
3. Polytechnique Montreal, 2500 Chem. de Polytechnique,Department of Mechanical Engineering,Montréal,QC,H3T 1J4