Patent attributes
A board for balance training has an upper footstep surface, lower bearing surface and a progressive series of concentric, cylindrical sub-frames depending from the lower surface which enclose progressively smaller framed-in areas of the bearing surface within progressively smaller framed-in crown-cavities defined by each. This progressive series ranges extremes of a major in size to minor, with none, one or more intermediates. All at least but the major sub-frame are selectively removable from the board for clearing way for progressively larger framed-in crown-cavities. Any of the sub-frames permit a training ball to roll freely sandwiched between the board and ground unless stopped against any portion of that sub-frame. Selectively utilizing a minor sub-frame over, conversely, exclusion thereof in favor of any of the progressively larger sub-frames, progressively changes the level of difficulty for trainees standing on the upper footstep surface.
