Students from ETH Zurich are developing an exoskeleton for paraplegics that they say more accurately mimics natural knee gait meaning it won't struggle on uneven terrain. Powered exoskeletons can give paraplegics or those with lower-limb weakness the ability to walk again. Mechanical engineers from ETH Zurich believe they have the solution. This prototype exoskeleton has one important addition that could make it able to cope with whatever comes its way. "Here with the Varileg we implemented the mechanical variable impedance, which is something special that no other exoskeleton has implemented at the moment. And the advantage of this is that we can mimic the human-like stiffness adaptation of the human knee and this also allows us to adapt to unexpected obstacles because we can say how stiff the knee should behave."