You can find this exercise on page 263 of the book Synergistic Golf.
Exercise Type: PILATES
Exercise Category: FLEXIBILITY, HIPS, LOW BACK, POSTURE
Sit tall with legs outstretched with feet slightly wider than hips. Arms reach out shoulder height to sides with palms down. Inhale to prepare. Exhale for 3 counts while rotating spine. Rotate slightly more on each breath to maximum. Inhale return to center lengthening through spine. Repeat same movement each side 3-5X.