Concludes: "Our results suggest that adverse reactions to chiropractic care for neck pain are common and that despite somewhat imprecise estimation, adverse reactions appear more likely to follow cervical spine manipulation than mobilization. GIven the possible higher risk of adverse reactions and lack of demonstrated effectiveness of manipulation over mobilization, chiropractors should consider a conservative approach for applying manipulation to their patients, especially those with severe neck pain". Spine (1st July 2005)