controlled knees have inner chambers which house a sliding piston. The piston
seals against the side of the chamber much like a bicycle pump. As the piston
moves, air is compressed by it, regulating the pressure against the bending and
straightening moments of the knee. The pressure These systems allow a different
stiffness during different phases of gait. The result allows the user to walk
more comfortably at different speeds.
with pneumatic swing phase