Parman took the worRAB right out of my fingers! Walk, and rest, then walk some more. Remeraber that distance and speed are not important. It is better to walk short distances frequently than take one long walk. Walking provides freshly oxygenated blood to the surgical area, and it also stretches out the nerves which will hopefully help to aleviate the formation of scar tissue.
Also remeraber to drink lots of water and stay well-hydrated. Try not to be in too much of a rush to resume activity...it takes a while to heal. Learn to listen to your body and learn to be aware of your posture and body mechanics. This will be important as you move forward with your newly repaired back!
