Healing time?

  I had a laminectomy of L4-L5 27 days ago. If I move in certain ways, I can still feel the twinge of pain in my buttocks area. No
  where near what I felt in the past, and no even needing medicaition. It is momentary, and relieved by getting out of the position I
  just moved into. My MDs office said this is normal  post surgery and that I have a long time to heal. I am walking
  30-60 mins daily and feel Im doing quite well, actually. But Im so curious as to what causes this painful twinge if the disk was
  removed (most if not all of it the surgeon told me). Is it from inflamation (inflammation) of tissue? Someone told me about something called
  nerve memory?
  Also, I may have walked a bit long on the treadmill (60 mins) at one time, vs breaking it up 30/30.  The next day my back felt a dull ache. And when I moved a certain way after sitting in a way that my back was NOT supported; I got a painful stab, and it was difficult to walk for a few minutes... very achy. I got scared.
  Is this to be expected throughout the healing?
  Please inform and help educate! Thanks
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The symptoms you describe are very typical following surgery, as a matter
of fact you seem to be doing very well, after surgery which is after all
a very traumatic process, there is a great deal of inflammation and
swelling in the area of the surgery which may compress the nerves to some
extent. This is so extreme that MRI scans following surgery are practically
unreadable due to all of the inflammatory reaction.
This will take several weeks to settle completely but it sounds like you are
nicely on course for a full recovery.