Fig. 2

Representative paths of the center of pressure (CoP) and of the center of mass (CoM) in the horizontal x–y-plane. The Feet-CoP, Total-CoP and the CoM of one trial for each of the three force instructions and the two arm configurations are shown. A Exemplary trial when standing on the ground in tandem stance (Off Beam – No Canes). The grey line represents the CoP and the black line the CoM. B CoP and CoM of one trial of the same participant when standing on the beam without canes (On Beam – No Canes). C. Six panels showing both the Feet-CoP (colored) and the Total-CoP (grey) for the three force conditions: minimum (green), preferred (blue), maximum (red); black lines show the center of mass (CoM). The two cane configurations are identified by the drawings at the top of each panel. The beam is the light yellow area bounded by thin lines for visibility. For all conditions on and off the beam, the participant stood in tandem stance with the same foot in the front