Chiropractic and osteopathy – how do they work?

For the past few years I’ve had a guilty pleasure. I’ve visited osteopaths and and chiropractors. Guilty, because I’m a science writer and know about the scientific question marks hanging over both professions. A pleasure, because I’m a science writer and spend much of my time hunched over a laptop – when you’ve got a bad back, there are few things more satisfying than having your spine popped like bubble wrap. Then cranial osteopathy happened.
Lying down wearing only my underwear in an osteopath’s front room, I was waiting expectantly for the back-popping to begin. Instead, to my toe-curling horror, he started lightly fingering my head and telling me he was channelling energy through the plates of my skull. With his touch, apparently, he’d reset my “internal rhythms” and cure my pain. I didn’t think my back could get much stiffer. It turns out I was wrong. With this unsolicited venture into a wacky branch of both osteopathy and chiropractic came a question I should have asked a long time ago: how much of these professions is scientifically legitimate and how much, as others have asked before me, is bogus?
I got an answer I was secretly not expecting. “Even in the case of low-back pain where the claims are most plausible,” says David Colquhoun, a pharmacologist at UCL and outspoken critic of pseudo-medicine, “there is little reason to believe that manipulation works. People get better at much the same rate regardless of treatment.”
Source  - Guardian