Movement: Grasping a fixed object - like the side of a wall - for support, straighten and swing one leg forward and backward. Keep the leg straight and make sure range of motion comes from the hips and not from flexing and extending the lower back. Only extend your range of motion as far as you can while generating the motion in the hips.
Repetitions: Perform all prescribed reps on one side, then on the other. This counts as one set.