Start in a quadruped position with your wrists directly underneath your shoulders and your knees directly underneath your hips. Your core should be engaged, and your spine should be in a neutral position.
With control, lift your knees one inch off the ground. Be sure to keep your back flat and your abs engaged.
From this position, extend your right leg straight behind you, then repeat with the left leg. Your back should remain in a neutral position the entire time, and the only movement should come from your legs. You should be in a high plank position.
With control, bend your right knee and slowly return your right leg to the starting position followed by the left leg. Be sure to keep your core engaged and your spine in a neutral position.