i am 65 yo female, had fusion L4/5 with hardware due to spinal stenosis and foramal narrowing 8 weeks ago. going back to work in 2 days. i have resumed many activites, cleaning,occasional caring for grandchildren,which includes lifting and carrying 19 lb. grandson. the day after one of these busy days i am very tired and sleep all day. i now am having pretty severe stiffness in legs and tightness (like a band) across lower back. the stiffness in legs gives me unsteady gait and i walk like someone who has been drinking. also, i can't stand for long periods duee to the lower back tightness. started PT 3 weeks ago and it gives me same problems as above, is this "normal" and to be expected? can you share your experiences?