It's my 4th day of recovery post op. I'm feeling pretty good with very little pain. I get up and walk up to 5 mins every 15 mins and not run out of breath. I could walk more but my back hurts. At the moment, I can stand almost straight up but just slightly bent at the waist. Am I overdoing or underdoing the walking? Any tips to relieve back pain without resorting to pain killers?