Hip motion is very important in the mechanics of your backswing. Studies show that golfers with more outward rotation than inward rotation of the hip are more likely to have low back pain.
The lead hip acts as a pivot point during the golf swing. This puts quite a bit of torque or twist on the hip. If the hip doesn't have enough motion, the force is transferred to the lumbar spine. Injury of the low back or sacroiliac area can occur.
Check with your doctor before golfing. You should do well with a good rehab program and training in preparation for golf. A physical therapist can help you by checking your motion and teaching proper stretches for your hip and low back.