The eccentric push up works on controlling the downward portion of the movement. You may want an easier push up variation than you'd use for regular push ups. Start in a high plank and twist your elbow pits ~45* inward. Slowly lower down to the ground using your push up variation. Press back up to the high plank quickly; you can use a different push up variation for this part, if that makes sense for you. For example, lower in a plank from toes, push back up on your knees.