| 摘要 |
A structure having an upper surface contoured to maintain the spine of a person lying horizontal on the mattress in the proper curvature regardless of whether the person is lying in the supine, prone, or side position; the upper surface having a convex shape in each of the lumbar and knee regions and having a concave depression in the sacral region, with reduced tapering end portions from the lumbar and knee regions to the ends of the support. |
