An adjustable support assembly is described for use with any prior art seating device having a post and a plurality of substantially horizontal legs. In some embodiments, the support assembly has a support with at least two voids for mounting to the post of the seating device, and at least one leg. The outer perimeter of the support is moveable outwardly with respect to the post of the seating device via selective engagement with one of the voids. Further, the attachment of the legs to the support provides a way to selectively lock the support to prevent rotation of the support about the post. A method of adjusting the support is also disclosed.
