(a) a main hinge assembly;

(b) an ankle hinge assembly;

(c) two ankle pivot points;

(d) a foot plate;

(e) a lower leg housing member;

(f) an upper leg housing member; and

(g) a cable;

wherein the main hinge assembly comprises a first elongated member and a second elongated member;

wherein the first elongated member is fixedly attached to the lower leg housing member and the second elongated member is fixedly attached to the upper leg housing member;

wherein the first elongated member comprises a gear and a unidirectional bearing;

wherein the gear comprises teeth;

wherein the unidirectional bearing is situated inside of the gear;

wherein the main hinge assembly further comprises a locking lever;

wherein the locking lever comprises teeth and a spring;

wherein the spring maintains the locking lever in an engaged position unless the spring is compressed;

wherein when the locking lever is in an engaged position, the teeth of the locking lever engage with the teeth on the gear, thereby maintaining the gear in a stationary position;

wherein when the gear is maintained in a stationary position, the unidirectional bearing only allows the first and second elongated members to move in one direction in relation to one another, that direction corresponding to the extension of a patient's leg at the knee;

wherein when the cable is pulled taught, the spring of the locking lever is compressed, and the locking lever is disengaged from the gear;

wherein when the locking lever is disengaged from the gear, the gear allows the first and second elongated members to move in two directions in relation to one another, those two directions corresponding to the flexion and extension of a patient's leg at the knee;

wherein the foot plate comprises a heel portion;

wherein the ankle hinge assembly is situated above the heel portion of the foot plate; and

wherein the cable connects the ankle hinge assembly to the locking lever.