This exercise will improve strength and motor control of your hip extensors.
Start on your back with your knees bent. Move your feet away from your buttocks and spread your toes. Pull a resistance band across your chest bringing your hands to the floor. Lift the right leg up and hold. Lengthen your lower back, contract your buttock muscles (glutes) and lift. Be sure to press through your whole foot and avoid arching your lower back or flaring your ribs. Repeat for the prescribed sets and reps.