Our massage ball provides targeted self-massage trigger point therapy by using specially designed high grip rubber balls and focused movement routines that help penetrate through layers of skin and muscle to massage deeply into your high tension areas. Yoga Tune Up's collection of Therapy Balls are made from rubber which is firm enough to deliver deep, targeted massage through multiple layers of tissue, yet flexible enough that it won't nip or drag against the skin. The idea is you place the balls between you and a hard surface, either the floor or a wall, and roll against it. This unravels knots, improves flexibility and relieves aches and pains..