You can find this exercise on page 189 of the book Synergistic Golf.
Exercise Type: DYNAMIC STRETCH
Exercise Category: FLEXIBILITY, LEGS - FEET, LOW BACK
Stand tall with feet together and hands down at sides facing outer thighs. Inhale to prepare and lengthen back of neck, dropping chin toward chest. As you exhale, roll down as if rolling back off a wall behind you, one vertebrae at a time. Allow head to hang and engage abdominals pulling belly button to spine. Bend down allowing hands and arms to drop weightlessly toward feet. Inhale at the bottom pausing for a moment, then exhale and reverse the process standing back up.