I did something initially that made it nearly impossible to move faster than the sloth from the Disney movie for a while. Once I got to the point that I could move almost normal, there were several instances where if I leaned and twisted just right I would have a shooting pain in my back, instantly lose all strength in my legs, and drop to my knees.

Physical therapy and taking it super super easy over a long time (2 years) helped me get back to normal. Initially I started with just walking, which actually helped quite a bit.