It always amazes me how delicate the back is. First did mine about 40 years ago trimming a privet hedge with some lopping shears - well, that branch is almost through - just a little twist will break it off. Wrong! I laid on the lawn for several minutes before I could crawl to the car and pull myself up. Did it again about 14 years ago sailing back from Maine - fortunately the wife and crew got me into range of a doctor who had the magic combo. Pain killer and muscle relaxant. Did it again this past winter changing out a toilet - those buggers are heavier than they look! Needless to say, the skis stayed in the shed! And now the docs only give you meds for 10 days - no more of the 30 day stuff.
Recommend you look into a program of stretching exercises - I find they work wonders. If you doc can't recommend something, look into a book called Stretching by Bob Anderson - I'm working on my second copy (wore out the first one).