Fig. 23.
Suspension from the pelvis.
A metal hip piece is fixed below the iliac crest and held in place by a belt which passes above the iliac crest of the opposite side ([Figs. 20 to 24]). This piece is attached to the thigh bucket by a joint shown in [figure 19] (see also [Fig. 22]), which allows both flexion and abduction of the hip, and which forms the suspension of the outer side of the limb. The inner border is suspended by means of a perineal strap, shown in [figures 21 and 22]. In figure 21 is shown how a suspending brace may be easily added. Figure 23 shows the action of a single hinge joint, allowing only flexion and extension at the hip joint. On [page 27] will be seen similar joints which, however, move on the pelvic attachment as well as on the thigh piece. The object of this is to prevent the pinching of the abdominal wall by the top of the thigh bucket when the patient sits. It is indispensable in short stumps. On [page 21] will be seen a joint which allows abduction of the hip, and thus relieves the strain upon the hinge joint; without it the latter is easily broken.
B. Suspension by means of braces (American method).—The American method of suspension has the advantage of leaving the pelvis free; the patient does not feel the pull of the hip piece. Besides, when the belt is used, if the patient sits down, the buttock on the side of the stump is raised, to an extent corresponding to the thickness of the bucket, an obliquity of the pelvis, which is both uncomfortable and unsightly, being produced. The braces being relaxed in the sitting posture, the patient can avoid this inconvenience; for the stump may be slipped partly out of its bucket, the upper extremity of which is then beyond the level of the edge of the chair. This position is very comfortable, because it is normal, but the patient must replace his stump in the bucket whenever he stands up.
Figs. 24 and 25
Braces composed of straps passing over the shoulders and down the front, attached to the bucket by buckles. Posteriorly they are joined together by a cross strap between the scapulæ, and beyond this are continued in the form of elastic straps.
This form of suspension is essential for those artificial limbs with a free knee-joint, in which, as we shall see, the braces serve to extend the joint.