The bottom side, which goes on the ground, has a hemisphere in the center, in some wobble boards, this hemisphere can be moved higher or lower to increase difficulty and therefore the effect.
The bottom side has a hemisphere in the center, this hemisphere can be moved higher or lower to increase difficulty. This was in some wobble boards. The bottom side has a hemisphere in the center, this hemisphere can be moved higher or lower to increase therefore the effect. This was in some wobble boards. The bottom side goes on the ground.