Fig. 2

Kinematics and kinetics of balancing responses following LL-NP/L perturbation. The first row shows interaction forces between BAR-TM and participant’s pelvis in the frontal plane. The second row shows the trajectories of COPx (solid lines) and COMx (dotted lines), while the third row shows GRFx trajectories. The fourth row shows COPy (solid lines) and COMy (dotted lines) trajectories, and the fifth row shows GRFy trajectories. The left column shows the balancing responses of the individual post-stroke prior to the training (experimental condition BEFORE_60 – blue line) along with the unperturbed walking trajectories (green line). The middle column shows balancing responses of the individual post-stroke after the training (experimental conditions AFTER_60 – blue line and AFTER_90 – red line) along with the unperturbed walking trajectories (green line). The right column shows balancing responses of the control participant (experimental conditions CONTROL_60 – blue line and CONTROL_90 – red line) along with the unperturbed walking trajectories (green line). Half a stride prior to and two and a half strides following the perturbation commencement are shown. Stride is defined as the period between two consecutive left-foot contacts. The trajectories displayed show mean values and standard deviations of twenty balancing responses while, for clarity, only the mean values of twenty blocks of three consecutive strides of unperturbed walking are shown. Underneath each column, six consecutive stance phases of both legs are schematically indicated to enable easier cross-referencing with other figures. Subscript 0 denotes stance phases of both legs for steps taken before commencement of a perturbation, while subscripts 1 and 2 denote stance phases of each leg for steps taken after the commencement of a perturbation. P/R – paretic/right; NP/L – non-paretic/left