Figure 3.

Plots of the responses in perturbation trials for a single direction perturbation applied to an operate (TX) rat’s stance. LP large perturbation, MP medium perturbation, SP small perturbation. Shown are :(A) the distance over time of the position of the phantom tip from rest. (B), the magnitude of the horizontal plane interaction force between an operate rat and the Phantom. (C) the magnitude of the horizontal plane ground reaction force at the right hindlimb force-plate sensor. Rats picked a strategy for how to distribute horizontal (‘shear’) forces among the individual leg’s ground reaction forces. Data is shown for operate rat number J490 (CoP shown in Figure 2). Data are plotted during each size perturbation, all in direction D (See Fig 1). Bias resting force was removed from the ground reaction force sensor and position is referenced to the rest posture. Data is plotted at each force sample acquisition from the sensors (15.8ms increments). Time is displayed both as the sample count, and as a 500ms scale bar in panel A. Note the small hindlimb force responses in panel C relative to the applied force in panel B in this rat.