I dont know wich spine level you are looking for but hopefully this could help
look at this web site and the referances used
http://www.mja.com.au/public/issues/...n10520_fm.html
regards
Santilli V, et al. Chiropractic manipulation in the treatment of acute back pain and sciatica with disc protrusion: A randomized double-blind clinical trial of active and simulated spinal manipulations. The Spine. 2006;6:131–137.
Herzog W. Forces required to cause cavitation during spinal manipulation of the thoracic spine. Clin Biomech. 1993;3:16–18.
Giles L, Muetter R. Chronic spinal pain: a randomized clinical trial comparing medication, acupuncture, and spinal manipulation. Spine. 2003;28:1490. [PubMed]
Lawrence V. Spinal manipulation for low back pain. A meta-analysis. ACP Journal Club. 1993;118:9.
Shekelle PG, Adams AH, Chassin MP, Hurwitz EL, Brook RH. Spinal manipulation for low back pain. Ann Intern Med. 1992;117:590–598. [PubMed]