Major issue, thought not the only one, I have lower back problems. Lumbar vertebrae 2,3,4,5.
issue, frequent lower back pain. Hurts to move.
Issue, I can't bend over very far without falling or hanging onto something. Some time I need a cane to walk with, but not always. Frequently have to get on floor in order to pick something up.
Issue, Pain in the back of thighs and calves. Hard to walk. Doctor says source of pain is lower back.
General issue, loss of strength-cause old age.
General issue, Loss of endurance, tire quickly-cause old age
There are others, but, you get the idea.