| 摘要 |
Back rest having a semi-rigid frame having the shape, in longitudinal section, of a shallow S formed by an upper concave portion and a lower convex portion, a cervical support affixed to and projecting from the upper end of the frame, a thoracic support extending downwardly from the cervical support along the median line of the frame, a lumbo-sacral support extending downwardly from the thoracic support, said thoracic and lumbo-sacral supports being formed with a groove to receive bony spinal prominences, and a kidney support on each side of that frame, said supports being of foam material.
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