If the pain is worse in the morning, resolves mostly or at least improves significantly as the day progresses and gets bad again in the evening, there may be no relationship with your back condition. It could be plantar fascitis. I had this several years ago. I didn't know what it was and was afraid to find out. I finally couldn't stand the pain. The "fix" was simple. once an orthopedist diagnosed it: a course of NSAIDS (use them as anti-inflammatories, not pain meds) and heel cups to change the dynamic of the foot's geometry. That did the trick. I will also tell you it took a long time for this to resolve (many months)because the condition was of such longstanding, but it did eventually go away. Now, if I think it's coming back, I resume NSAIDS and get out my heel cups before it has a chance to become "just-this-side-of-debilitating" again. Hope this helps.