Some people bruise much more easily than others. In most cases, aside from athletes and the denser muscles of the body, just hovering the tool over the muscle in order to use its vibration capabilities is all that's needed. We would recommend going over the first topic in Week 1 one more time on the use of the tool and body mechanics to be sure you're not overdoing the pressure. In many cases, the bruising is going to happen with almost any pressure and is a harmless side effect.