This exercise will help you improve your flexibility to increase your range of motion to make a better swing. Try this flexibility exercise that targets arms, shoulders, obliques and core muscles.
If you have limited side bend, then you will also be limited in your spinal rotation because one motion cannot happen without the other motion. Any limitations in this area will cause you to slide or sway in your golf swing. Improving your range of motion so you can sidebend will help you make a better backswing and follow-through.