You can find this exercise on page 239 of the book Synergistic Golf.
Exercise Type: YOGA-STRETCH
Exercise Category: ABDOMINALS, BACK, FLEXIBILITY, LEGS - FEET, LOW BACK
Place your hands on a wall, shoulder width apart at shoulder height. Step back until your arms are completely straight keeping your feet directly under your hips. Keep your back straight as you bend forward allowing your head to drop below your elbows. Take several breaths then walk toward the wall to release the pose.