TheraBand Mini Ball, Small Exercise Ball Small therapy ball strengthens key muscles in the abdomen, enhances core health, and improves endurance, posture, and balance when used in rehabilitation, strengthening, and toning exercise programs Place small pilates ball under lower back when performing crunches and other ab workouts to create a more challenging and intense abdominal exercise routine Position soft ball between your body and the floor or wall to improve stability, balance, and muscle endurance, especially when used in a shoulder strengthening or core strengthening program Anti-burst 9 inch diameter ball is designed to remain elastic and squishy when fully inflated and is slightly textured to stay in place while performing yoga, pilates, or physical therapy exercises Pump not required, can be easily inflated with included tube and breath, comes with instruction booklet that includes various abdominal, upper body, lower body, and shoulder rehabilitation exercises