My experience with chiropractors and one osteopath:
Circa 1994, my last winter in rural North Dakota, I hurt my back while shoveling snow after an unusually fierce blizzard which blew in just the wrong direction and left an enormous hard-packed snowdrift on my long driveway. Since then, any time I lift something too heavy, my back hurts for days or weeks.
On several occasions, the pain was bad enough, that I got desperate enough to go to a chiropractor. The manipulation gives me significant relief that lasts, literally, about ten minutes. By the time I get back to my car, I'm in pain again.
Once I took a "Healthy Back" class at the YMCA in Fargo, taught by a chiropractor who told us that most chiropractors are quacks. He told us that most back pain is caused by damage to soft tissue, not by misalignments in the spine. And that the key to a healthy back is to stretch and strengthen the muscles of the back. Stretch the tight ones, and strengthen the weak ones, and to this end he gave us a program of exercises.
When I was living in Spain, I hurt my back by carrying a microwave oven up about 4 flights of stairs. The pain was so bad I could hardly walk, and past experience suggested I likely would be unable to jog for a month and a half. In desperation I looked in the phone book for a chiropractor, and what I found was an osteopath.
She began with a back massage to loosen the muscles. Then she twisted me up like a pretzel, in much the same way as a chiropractor, but without the "snap." Just a really hard stretch. When she was done I was free of pain and walking normally. I asked her when I should come back, because chiropractors always want you to come back multiple times. Her reply was that it was not necessary. The pain did not return and a week later I was jogging again.
Half a year later I moved, again had to carry the microwave up the stairs to the new apartment, and again my back was crippled with pain. I went back to the osteopath, with the same results.
When I returned home to North Dakota, I tried to find an osteopath, for reference for future back pain, but the only ones I could find did not treat that sort of injury. I had a massage therapist who rented a room in a chiropractor's office, and I described to the chiropractor what the osteopath had done, and asked him if he could do that, but he was reluctant to do anything other than his usual thing.
I regularly do a yoga-dead-bug-style stretch, which is as near as I can come on my own to what the osteopath did to me, and I think it helps, but I've never found anyone here who does what the Spanish osteopath did. My new (as of maybe 6 months ago) primary is a D.O. but I've never had this conversation with him.