Fig. 7From: Passive-elastic knee-ankle exoskeleton reduces the metabolic cost of walkingDetailed view of the exoskeleton from the back illustrates that the rope r3 (blue dashed line) was not well-aligned with the ankle frame attachment (red lines are at 90° angles). The engagement of r3 enables ankle plantarflexion assistance, but it is likely that energy is lost due to the angle (β = ~ 45°) of the rope with respect to the shankBack to article page