Since the risks in stunt work are high, every move and position must be correct to reduce the risk of injury from accidents. Examples of practical effects include tripping and falling down, high jumps, extreme sporting moves, acrobatics and high diving, spins, gainer falls, “suicide backflips,” and other martial arts stunts. [citation needed] Stunt airbags (or “stunt mats”), large, deep airbags that may be the size of a small swimming pool, are typically used by professional stunt performers to cushion their landings from staged falls from heights.