The SMAI Balance Disk Cushion is designed to challenge your core, by creating a very unstable and difficult surface to stand on, sit on, or lean on. The disc should be partially inflated, to create a non-rigid surface. You can then perform standing balance exercises by standing on one foot, sitting balance exercises by placing on a chair and sitting on the disc, or perform push-ups or pilates bridges with hands placed on the disc to create additional challenges. To adjust the challenge level, yo