Standing on a step, holding a weight in your hand above your head, slowly drop your opposite heel in front of the step. Touch the floor. Come back up slowly.

Make sure to keep the heel of the foot on the step in contact with the step throughout the movement.

Do not transfer weight through the leg touching the floor. Do not hinge the hips.

Will help:

This is one of these magic exercises which will help most conditions from balance issues to post-op back operations.