A spring-loaded low back brace. A preliminary report.

All of the low back braces available today are fabricated to provide anteriorly or posteriorly directed forces . None accomplishes satisfactory immobilization, and, in fact, braces with a high thoraco-lumbar purchase area increase lumbosacral motion (1) . Attempts to improve the lumbar immobilization by applying increased abdominal pressure are useful to a limited degree, as in the Williams brace, but the use of this technique as an ultimate goal raises problems of more remote secondary effects on the cardiac and respiratory systems (2) . The spring-loaded back brace (Fig . 1) was conceived to employ concepts that were presented at a recent Spinal Orthotics Cor `hence: 1. "The critical buckling load of a semi-flexible rod i' 'amatically changed as one imposes variations in the end-point conk . he rod. Milwaukee braces probably do this" (2) . 2. With reference to present braces, Keay (2) stated "it is ineo:rect. to impute to the brace the ability to `hold on up' as if it acts — a structural prop . This type of action implies that there is, in the I =-_ the capacity to avoid or withdraw, that the brace can `induce' a ph'siologic neuromuscular response of modified behavior or position ." The brace described here was designed to impose "end-point" variations and provide a stimulus to withdrawal . These features were accomplished by fabricating a broad transverse proximal molded plastic band of Orthoplast so that it was fitted to conform to, and curve under, the lower rib cage in the manner of a hemipelvectomy socket . The distal molded transverse plastic band was fitted over the pelvis and iliac crests (Fig. 2a and 2b) . Both were joined by two springy loaded supports. By pushing down on the uprights the patient compresses the springs and loads the brace . The Velcro straps are employed to retain the loading