1. Figure 1. Experimental setup showing subject with stroke training with Department of Veterans Affairs-Massachusetts Institute of Technology ankle robot (anklebot) in seated position while playing visually evoked, visually guided ankle targeting video game. Arrows denote motion of vertical gates that serve as targets for anklebot- and foot-controlled cursor. Subject is required to either plantar flex (left column) or dorsiflex (right column) his or her ankle from current position to move cursor toward appropriate approaching gate with anklebot assisting "as needed." Bottom panel shows close-up view of subject's foot movement in either dorsiflexion (DF) or plantar flexion (PF) while playing video game or, during stiffness assessment, when ankle is passively stretched by anklebot to measure torque-angle data used to estimate passive ankle stiffness. Knee brace (partly seen) is mounted to fixed plate that supports anklebot and restricts translational (but not rotational) knee movements, effectively isolating ankle movements in either DF-PF or inversion-eversion planes. Roy A, Forrester LW, Macko RF, Krebs HI. Changes in passive ankle stiffness and its effects on gait function in people with chronic stroke. J Rehabil Res Dev. 2013; 50(4):555–72.http://dx.doi.org/10.1682/JRRD.2011.10.0206 ResearcherID/ORCID: Anindo Roy, PhD: E-4312-2012