Before revision: Structure 255 px| The roller and underside of a rocker-roller board The underside of a sphere-and-ring board Lower limb proprioceptive work The user stands on a board or other platform which is on top of an unstable ground-contacting member, the fulcrum.
After revision: Structure The roller and underside of a rocker-roller board The underside of a sphere-and-ring board Lower limb proprioceptive work The user stands on a board or other platform which is on top of an unstable ground-contacting member, the fulcrum.