Back rest cushion

Claim 1

A therapeutic back support comprising: a unitary cushion of resilient material, having a forward back engaging side, said cushion having a lower end adapted to rest on a support surface for a seated person and having an upper end extending above the thoracic vertebrae, said cushion having a width about equal to the width of a human back and being symmetrical about a vertical central plane, the back engaging side of said cushion having merging concave and convex surfaces, said cushion being formed to a first convex surface adjacent to the lower end and centrally thereof for abutting the coccyx of the person and having concave surfaces laterally outwardly of said first convex surface, merging with the first convex surface and positioned for receiving the upper buttocks of the seated person, at approximately a lower-central location the cushion being formed with a second convex surface positioned to abut the lumbosacral region of the person's spine across the lower back and spaced from the first convex surface with a concave surface interposed therebetween, the upper end of the cushion being formed with a central third convex surface for abutting the thoracic region of the person's spine and spaced above the second convex portion by a merging concave surface, and the cushion being cut away to left and right of the central third convex surface to provide open space to freely accommodate movement of the upper torso, arms and shoulder blades of the seated person.