At 40 years old I still have never injured my back, but I am starting to sense that I push my luck more often than I should. I was unloading a load of red oak rounds this weekend and starting getting signals from my lower back that the twist and heave was a bad idea. Can you guys trace injuries or chronic conditions to firewood splitting/lifting? I am wondering whether I am inviting a retirement as an invalid by pushing my luck here? What about shoulder/back injuries connected to manual splitting (axe/maul/sledge)? I am 6'4"/250lbs and have always figured my body was just about indestructible, but little aches and pains (6 months to recover from some sort of shoulder pain last year) suggest that I am mortal now.