Alternating Bird Dog Knee to Elbow
Get on all fours with your hands underneath your shoulders and your knees underneath your hips. Keep your core tight as you simultaneously extend your left leg behind you and reach your right arm forward so they are parallel with the floor. Then bend your knee and elbow and try to touch them underneath your body while keeping your back straight. Extend them parallel once more, then return to the start to complete one rep. Continue, alternating sides.