I also have spinal stenosis and arthritis in the back. I find water aerobics and swimming helps. Ever since I started water therapy I have felt 90% better. I wasted my time going to a physical therapist. The only thing she could tell me I could do was monotonous back exercises every day. All she had to tell me was I need to take water exercises and that would help. My back use to hurt so bad I could not even sleep at night. Now I get many pain free nights of sleep.