A simple, inexpensive prosthetic foot is provided incorporating a
cushioned ankle including an ankle block formed of a resilient material
or bladder having desired compliance and energy return characteristics.
The ankle block is sandwiched between a foot element and an ankle
element. One or more openings extends through the ankle block with a
substantially transverse orientation relative to a forward walking
motion. The size and shape of these openings, as well as the insertion of
different types of stiffeners therein, provide desired performance
characteristics to the ankle block. When the ankle block takes the form
of one or more inflatable bladders, the pressure within these bladders is
individually controlled by valves to provide desired performance
characteristics to different portions of the prosthetic foot. A pump
system can also be used to control and generate fluid pressure into these
bladders. A preferred pump system generates fluid pressure based upon the
movement of the amputee onto two telescoping pylons that are connected to
the prosthetic foot.