The back is the captain of the golf swing. The back is involved in the takeaway, the downswing and the follow-through. If you have any pain in any of your back muscles, swinging a golf club will either be painful or impossible. If it is painful and you attempt to play, you will do even more damage and you won't be able to play much longer.
You must attack the ball with the muscles in your front shoulder. This is where your power comes from, and you must get excellent shoulder movement involved if you want to get any distance off the tee. Tender shoulder muscles will keep you from snapping into the ball and getting significant height and length on your shot.
Lower-body muscles (buttocks)
In addition to the explosion provided by your shoulder, you must also get your lower body into the ball. Your hips will turn as they pass through the hitting zone, and your buttocks or gluteus maximus muscles must turn and contract in order to get the most out of your shot.