This is copied from Arthritis Research UK. It contains some nice easy exercises that you can do even if your back hurts. but if pain persists contact you Osteopath rather than your doctor.
Back pain is common but most cases aren’t caused by a serious problem. Most cases of back pain get better on their own within a few weeks.
Stay active. Bed rest for more than a couple of days makes it harder to get going. Gradually increase your normal activities and do regular exercise.