Starting Position: Holding the TRX handles or foot cradles in each hand, turn yourself to face the anchor point with your feet wider than hip-width and both facing forward. Bend at the hips, pushing them backwards while maintaining your weight over your heels and using the TRX to assist you keep your balance. As your lean backwards, extend your arms forward at chest height with palms facing towards the floor. Keep your head up, looking forward throughout this movement.
Rotation Movement: Exhale and slowly rotate your arms at the shoulders without turning your head until you reach a point of tension. The leading arm will rotate behind your torso while the trailing arm will simply move across the front of your body. Hold briefly, inhale, then exhale and rotate in the opposite direction.
Exercise Variation (1): To progress the exercise and mimic the golf swing more closely try moving your feet together and change your starting position where you are not bending over, but assuming a slightly bent-knee (1/4 squat) position. Extend your arms forward towards your knees rather than to chest level (pushing down on the handles of foot cradles) and rotate as described above. This rotation will exhibit more pivoting off the back foot. Change your head position to look towards the floor.
Exercise Variation (2): Progress the movement to a windmill to increase torso rotation for your golf swing. From the same starting position described in the first progression, rotate both arms together in each direction while keeping your head fixed and facing the floor. This movement will exhibit a greater degree of pivoting off the back foot.