According to the Institute of Medicine in the report Relieving Pain in America: A Blueprint for Transforming Prevention, Care, Education, And Research released in 2011, Chronic pain affects an estimated 116 million American adults- which is more than the total affected by heart disease, diabetes, and cancer combined and costs the nation $560-635 billion each year in medical treatment and lost productivity. Their recommendations included the importance of promoting self-management of pain as well as tailoring pain care to each patient's experience as pain varies from patient to patient.  

References: 

• One National Center for Complementary and Alternative Medicine funded study of 90 people with chronic low-back pain found that participants who practiced yoga had significantly less disability, pain, and depression after 6 months.
• In a 2011 study funded by NCCIH, researchers compared yoga with conventional stretching exercises or a self-care book in 228 adults with chronic low-back pain. The results showed that both yoga and stretching were more effective than a self-care book for improving function and reducing symptoms due to chronic low-back pain.
• Sherman KJ Cherkin DC, Connelly MT, et al. Complementary and alternative therapies for chronic low back pain: What treatments are patient willing to try? BMC Complementary and Alternative Medicine. 2004; 4:9. 
• " yoga appears to be an effective treatment in chronic neck pain with possible additional effects on psychological well-being and QOL. "
• Pai S, Sundaram LJ. Low back pain: an economic assessment in the United States. Orthop Clin North Am 2004;35:1-5
• Van Tulder MW, Koes BW, Maimivaara AV. Outcome of non-invasive treatment modalities on back pain: an evidence-base review. Eur Spine Journal. 2006;166:450-457
•  Craniosacral Therapy for the Treatment of Chronic Neck Pain