Position a weighted bar across your upper back holding the ends with your hands to keep it stable. Alternately, you can do this in a squat rack to more easily get into the starting position. Stand erect with your chest out and your shoulders back, maintaining the natural curve in your back and knees unlocked. Your feet should be about hip width apart. This is your starting position.
Staying erect, initiate the movement by stepping back with one foot about 2 feet, keeping your hips facing forward as the toe of your back foot makes first. Then allow both knees to bend and descend just short of allowing your trailing knee to touch the floor.
Your body should continue to be upright. Don't lean forward or allow you back to round. Press back up by pushing through your back foot maintaining balance as you return to the starting position.
Repeat on the opposite side, and repeat for the desired number of repetitions.