"Conclusions: Spinal manipulation, particularly when performed on the upper spine, is frequently associated with mild to moderate adverse effects. It can also result in serious complications such as vertebral artery dissection followed by stroke. Currently, the incidence of such events is not known. In the interest of patient safety we should reconsider our policy towards the routine use of spinal manipulation." Edzard Ernst, Journal of the Royal Society of Medicine (July 2007) (J R Soc Med 2007;100:06-0100.1-9)