Starting Position: Stand with your feet together, holding a dumbbell in your left hand. Brace your abdominal / core muscles to stabilize your spine. Pull your shoulder blades down and back without arching your low back. Maintain these engagements throughout the exercise.
Downward Movement: Inhale and slowly lift your left leg a few inches off the floor as you begin to bend forward at the hips. Balance on your standing leg. Try to keep the torso absolutely rigid with no sway, shift or rotation. Keep the back flat and the head aligned with your spine.
As you bend forward allow your left (dumbbell) arm to straighten toward the floor. Do not allow the torso to rotate or the shoulder to droop toward the floor. Continue bending forward, allowing only a slight bend in the knee until your torso is at, or near horizontal to the floor and your arms hang straight down from your shoulder. Maintain your balance by keeping your weight into the heel of the standing foot. Try to straighten your standing leg and point the toes to help with control through the movement (not illustrated).
Upward Movement: Exhale and slowly bring your torso back to a vertical position with your left arm (holding the dumbbell) at your side.
Exercise Variation: As this technique is mastered, the exercise intensity can be progressed by: (1) Switching the stance (supporting or balance) leg (i.e., holding a dumbbell in the left arm and lifting the right leg rather than the left leg). This increases the need for balance and stabilization within the body; (2) using heavier resistance; (3) bending over and / or lowering the hips closer to the ground by increasing your knee bend; and (4) standing on unstable surfaces (e.g., Airex pad).
Try performing this exercise alongside a mirror to monitor any change in your back or shoulder position and to check for trunk rotation.