Twisted Bird Dog Get on all fours, with your knees under your hips and your hands under your shoulders. Remember to keep abs engaged and keep your back flat. As you extend your right leg out straight, open up your left shoulder for an oblique and back twist. Round your back and head to connect your left elbow with your right leg under your body. Extend right hand and left leg back out for one complete rep. Image Source: POPSUGAR Photography