Status of the above-knee suction socket in the United States.

1 HE above-knee suction socket constitutes a means of attaching an artificial leg to the stump of an amputee without necessity for the conventional pelvic band, a metal hip joint, or other types of suspension harness (Fig. 1). The leg is held on by the slight vacuum created in the socket each time the leg is lifted from the ground, the pressure usually being controlled by a valve installed in the lower portion of the socket. Accurate functional fit of the socket, as distinguished from the conventional "plug" fit, permits the creation of negative pressure, gives a wider range of muscular control of the leg, and provides comfort while walking or sitting. Because the conventional belt and hinge joint are eliminated, the suction socket gives the above-knee amputee more freedom and less interference with clothing. The leg feels more like an integral part of the body, a feature which tends to decrease the sensation of dead weight and to improve sense of position. Reduced piston action of the stump in the socket results in greater toe clearance during walking. No stump sock is necessary. Any adductor roll is corrected. And finally, active use of the stump muscles causes them to develop instead of becoming atrophied.3