Thanks for the interesting take.
I've been running for 40 years. I suffered from knee and hip pain from it, until I read about the biomechanics of running. I ran doing the "heel strike", where the heel hits first. I could feel the shock in my knee and my hip with every stride.
I decided to switch to "ball strike" where I landed ball of the foot first and then rolled onto the foot. I did not feel the shock in my knee or hip after that. A couple weeks later, the joint pain began to subside, and for the last decade has not bothered me.
It takes a while to switch to ball strike, now it feels perfectly natural. Try this experiment. Run with your shoes on, and note your heel strike. Take your shoes off and run again - you'll run on the balls of your feet. This was the epiphany for me.
Running also builds up your heart, lungs and muscles quickly, but the tendons and joints and bones need years to adapt. A lot of people get into trouble by feeling strong and overdoing it. Ya gotta hold back and give it years.
I agree that if you're still having trouble with running, biking is a great alternative.
With your back, take the time to do proper back strengthening exercises. They greatly helped reduce the rate and severity of my repeated back injuries. I strongly recommend talking to a doctor to get a regimen of these exercises. They paid off for me big time. More that once I thought oh crap, I hurt my back again. But nope! Woo-hoo!
I'm not at all suggesting that tradesmen don't get injured on the job and the accumulation of such can be crippling.