Come to a hands and knees position. Engage your abs. Keep your spine in a neutral position; avoid any excessive sagging or arching. Pull the shoulder blades toward your hips.
Exhale. Keeping the knee bent, slowly lift the knee outwards and upwards toward the side. Try to move the leg without causing movement in your torso. Hold this position briefly, while keeping a stable torso and head level with your spine.
Inhale and slowly lower your knee back to the floor.
Repeat and switch legs.