Hi, after attending a summer course where we trained using equipment like wobble boards/cushion and similar to boost strength, I have decided to buy one for myself as I feel it really helped with strength which is something I need to improve. But I can't decide whether to buy a wobble board like this one: http://www.physioroom.com/product/PhysioRoom.com_Wooden_Wobble_Board_40cm/3183/39364.html which apparently helps whole body/core stability or a wobble cushion such as this: http://www.physioroom.com/product/PhysioRoom.com_NEW_Air_Stability_Wobble_Balance_Rehab_Cushion_35cm/3184/39222.html?gclid=CJL759vk0M4CFWgq0wodpKgJbQ which is supposed to be for ankle and foot strength. I am reluctant to buy both, certainly at the same time, so opinions on which one is better/which one to buy now would be gratefully received.