I occasionally have lower back pain and go to a chiropractor to get relief. Several years ago I was going to a chiropractor who told me that he was going out of town for a couple of weeks. I asked him what I should do while he was gone.
He suggested that I find someplace where I can hold onto something that will let me hang up off the ground, like the rafters where the ceiling in my garage would be if it had a ceiling -- about 8 feet from the floor. So each morning I go out to the garage, pull out the step ladder, and grab hold of a 2 x 4 overhead. I step off the ladder and kick downwards one foot after the other for 30 to 50 kicks, more if my hands hold out. Then I step back onto the ladder and come down, put the step ladder away, and go about my daily routine.
A 2 x 4 is not the best thing to hold on to -- I'd rather have some sort of horizontal bar. But I have rafters and no bars, so I do with what I have. I do get calluses on my fingers, and I still have back trouble now and then. But I haven't had such severe trouble since I've been hanging out in the garage every morning.