You can find this exercise on page 248 of the book Synergistic Golf.
Exercise Type: PILATES
Exercise Category: ABDOMINALS, FLEXIBILITY, LOW BACK, STRENGTH
Sit tall with knees bent, legs together and feet flat on mat. Arms are reaching overhead. Inhale to prepare. Exhale and roll back behind tail bone starting with pelvis. Roll back only as far as abdominals can stay activated with feet still flat on floor. Spine will be rounded with chin down. Inhale and roll back up to seated starting position. Complete 10 repetitions with control and focus on breathing.