Not only will you build a lot of strength during this arms and abs workout, but you're going to get your heart pumping and break a major sweat. By the end, your entire body is going to feel the burn—it's not going to be easy, but I know you can do it.
Shoulder Tap，How to: Start a kneeling push-up position with wrists under shoulders and body forming straight line from head to knees. Keep hips level, lift left hand and tap your right shoulder. Return to start and repeat with the other arm. That’s one rep. Complete 10.
You can also try other method, such as, doing sit-up. This product may help you. It's a adjustable sit-up trainer and it's very convenient.