Aquatic therapies are used to restore step initiation in people with locomotor disabilities. However, there is lack of evidence of underlining mechanisms of gait initiation in water. We investigated center of pressure (CoP), vertical and anterior-posterior impulse forces, and kinematics of the first step performed in water in comparison with overground walking. The peaks of anticipatory postural adjustment (APA) and the sections of CoP trajectories were longer in water than on land. Impulse forces were increased in water compared with land. Range of motion (ROM) of ankle joint increased in water while knee joint ROM did not change. We suggest that the aquatic environment may facilitate gait initiation training by allowing a longer step execution with greater stimuli and imposed resistance for the phases of gait initiation.
Marinho-Buzelli is with the Rehabilitation Sciences Institute, Verrier the Dept. of Physical Therapy, and Popovic the Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Onatrio, Canada. A.M.F. Barela, J.A. Barela, and Celestino are with the Institute of Physical Activity and Sport Sciences, Cruzeiro do Sul University, Sao Paulo, Brazil. Popovic is with the Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada.