Spiky massage balls can be used for self massage, releasing uncomfortable muscles and relieving tension. They can also help release toxins and improve circulation. To use, simply roll the ball around the area in need of a massage. Alternatively, in the case of tight back muscles, place the ball between your back and a wall and move from side to side, or up and down. It also feels great to massage the soles of your feet by sitting in a chair and rolling your foot over the ball on the floor.