The Plank Tap exercise works your shoulders, abs, obliques, hips, and legs.
This next exercise, not only strengthens your core but really works you obliques. So we get setup, when you get that right elbow right under your shoulder. (??) and we're gonna do a souped up version of the side plank. hand goes to your hip. You wanna raise your hip off the ground. Reach your hand up over your head, look about it for balance. Take that hand back down to your hip and dip your hips to the ground. And right back up. So reaching up, looking up using that balance. Keeping that elbow directly under that shoulder. Really working those bottom obliques.