How effect is this for back neck pain?
is a 2010 review article in a journal on manipulation, by chiropractic researchers. It concludes "Spinal manipulation/mobilization is effective in adults for: acute, subacute, and chronic low back pain; migraine and cervicogenic headache; cervicogenic dizziness" and "thoracic manipulation/mobilization is effective for acute/subacute neck pain". However, it also states that evidence is inconclusive for a number of other treatments, including "cervical manipulation/mobilization alone for neck pain of any duration, and for manipulation/mobilization for mid back pain".
Source: Chiropr Osteopat. 2010; 18: 3.
in a family practice journal states that manipulation for low back pain is unsupported, and may not be cost-effective.
Source: Am Fam Physician.
2012 Feb 15;85(4):343-350.
So, the literature isn't exactly consistent. Personally, I've seen some good results from shadowing a couple OMM docs, but N≈15 patients doesn't make a good data set, and I wasn't able to follow up with any of them. I also believe that skill and training have a lot to do with the results, whereas any prescription for X mg of Y drug is the same no matter who prescribes it, diagnosis skill aside.
Edit: On topic, if you localize well enough, you really shouldn't need that much rotation or force. For example, I've had a neck click back into place several times just by approaching the barrier while I was localizing. I usually don't need to go much beyond ~45 degrees rotation or sidebending for C2-7.