(a)
(b)
Figure 6: (a) Effects on dynamic joint stiffness of the ankle joint on the affected side: dynamic joint stiffness decreases in the beginning of the stance phase in (ii) “heel” and (iv) “all” conditions, whereas stiffness increases in the late stance phase in (ii) “heel,” (iii) “fifth,” and (iv) “all” conditions, which are similar to that of walking in normal subjects [9]. (b) Effects on COP trajectory on the affected side. The posterior position of COP in the conditions (ii) and (iv) moves backward at the beginning of the stance phase, whereas the anterior position in the conditions (iii) and (iv) moves forward at the end of the stance phase.