Patent ID: 8568281

Claim:
An exercise apparatus comprising: a) a rectangular support and a base for holding the rectangular support above the ground; b) a single flexible, rectangular gas filled cushion secured to the support, the cushion having a body with a dome-shaped upper surface, a bottom surface, a length, a longitudinal axis, the cushion including a peripheral rim along at least a portion of edge of the bottom surface of the body, wherein the apex of the upper surface of the body extends along the length of the body parallel to the longitudinal axis of the support for creating instability when exercising; c) a retainer for securing the cushion peripheral rim to the support, wherein the peripheral rim is sandwiched between the support and the retainer; and d) hand releasable fasteners for fastening the support to the base, wherein the hand releasable fasteners can be released without tools for using the cushion without the base.