Stroke survivor, 6mon post stroke resulting in right-sided hemiparesis, 53yrs old, had completed a 2mon rehabilitation program prior to the study. He underwent 30 training sessions with the Balance Assessment Robot (BAR™) within a 10-week period, each consisting of 10-15min of unperturbed treadmill and 30-45min of perturbation training. Perturbations were delivered in the forward, backward, left and right direction, occurring every 6sec, at the left leg initial contact and the right leg initial contact. Two training sessions were spent to determine adequate treadmill speed (0.4m/s) and perturbation amplitude (60N), followed by the first assessment session. After the last training session, assessment was repeated using the same parameters plus 90N perturbation amplitude.

Healthy male, height- and weight-matched to the Case. He was assessed according to the same protocol as the Case using the Balance Assessment Robot (BAR™) at perturbation amplitudes 60 and 90 N.

The BAR™ has got six degrees of freedom (DOF) that interface to the pelvis of a walking subject. Five DOFs (translation of pelvis in sagittal, lateral and vertical directions; pelvic rotation and pelvic list) are actuated and admittance-controlled, providing transparent haptic interaction with negligible power transfer; the remaining DOF (pelvic tilt) is passive. The BAR™ is capable of delivering perturbations in the directions forward/backward and left/right, but for the purpose of this study only "outward" perturbations in the frontal plane were considered.

For the purpose of qualitative assessment of kinematics and kinetics

For the purpose of qualitative assessment of kinematics and kinetics

For the purpose of qualitative assessment of kinematics and kinetics

For the purpose of qualitative assessment of spatio-temporal characteristics of stepping

For the purpose of qualitative assessment of spatio-temporal characteristics of stepping