The ankle is of fundamental importance during locomotion as it is the first major joint to transfer the ground reaction torques to the rest of the body. Similar to the role of muscles and tendons in the musculoskeletal system, a prosthesis may benefit from cable-driven systems, specifically Bowden cables, to actuate joints. For an ankle–foot prosthesis, Bowden cables allow the placement of the motors and gearboxes away from the distal parts of the limb and near the center of gravity of the user, reducing the metabolic cost. A mass at the feet increases the user metabolic cost by 8–9%/kg during walk, while a mass carried at the waist increases the metabolic cost by only 1–2%/kg [1]. Bowden cables also allow for flexibility on the customization of the prosthesis, especially when long residual limb would limit the amount of space available for the active components.
Currently available ankle–foot prostheses...
