Subject No Perturbation 1 Mean ± SD FOE Paretic Mean ± SD No Perturbation 1 Mean ± SD FOE Non-Paretic Mean ± SD Visual Inspection of Performance Type S1 0.7 ± 6.7 -7.6 ± 4.3 -2.5 ± 4.1 -1.7 ± 5.8 none 1 S2 -3.8 ± 8 -8.5 ± 7.2 -3.2 ± 7.3 5.6 ± 3.8 none 1 S3 -0.2 ± 4.2 -20.4 ± 5.0* -1.4 ± 6.2 -13.7 ± 7.8* mild to moderate 2 S4 1.6 ± 3.4 2.3 ± 2.0 -3.8 ± 1.5 -0.5 ± 3.8 mild to moderate 1 S5 -8.4  ± 6.9 -39.0 ± 4.2* - -10.5 ± 4.2 -21.4 ± 4.0* - moderate to severe 3 S6 -10.7 ± 7.2 -31.2 ± 6.4* - -6.7 ± 5.2 -21.9 ± 1.8* - moderate to severe 3 S7 -1.9 ± 6.4 -37.7 ± 8.5* - -3.0 ± 8.2 -7.1 ± 1.7* - moderate to severe 3 S8 2.6 ± 1.9 -5.47 ± 2.7 -1.5 ± 3.9 -7.0 ± 2.5 none 1 S9 -4.79 ± 1.9 -10.49 ± 3.27* -0.47 ± 3.9 -18.52 ± 6.65* mild to moderate 2 *denotes significant difference from no perturbation conditions -denotes significant difference between paretic and non-paretic sides type 1: normal Response type 2: mild to moderate impairments type 3 moderate to severe asymmetric responses

Table 2: Average Net Heading Responses at the end of the trial for each subject in each phase of testing. Negative values indicate undershooting.