According to a recent review published by the Agency for Healthcare Research and Quality, the benefits of complementary and alternative therapies for back and neck pain—such as acupuncture, massage, and spinal manipulation—are modest in size but provide more benefit than usual medical care. While these effects are most evident following the end of treatment, the authors of the report noted that very few studies looked at long-term outcomes. Back and neck pain are important health problems that affect millions of Americans, and back pain is the most common medical condition for which people use complementary and alternative medicine (CAM).
Source: http://nccam.nih.gov/research/results/spotlight/100110.htm?nav=rss