Fig. 2

a Sensor and tactor location. b Representative sample data from one participant with PD during the A/P dynamic weight-shifting exercise. Images shown in the top panel indicate movement directions corresponding to the movement trajectories shown in the bottom panel. Solid blue and red lines shown in the bottom panel represent the target motion (generated by custom software after measuring the participant’s 90 % of LOS in the A/P direction) and participant’s motion, respectively. Dashed black lines represent the participant’s 90 % of LOS in both the anterior and posterior directions