They are used one at a time or in pairs, on the ground exercises, in combination with other props, with machines: reformer, cadillac or chair?. When exercising, they add variety and challenge to already known exercises. They affect balance and stability by resisting rotation. They differ from other props because of their instability at the rotational level, in the transverse plane. Both bilateral and unilateral movements are made. You can do exercises supine, prone, in kneeling, sitting or lying positions. Training with them requires a lot of stability, mobility and coordination.