Alternative therapies: putting chiropractic under the clinical spotlight
The therapy is not proven to be effective for many disorders, despite its founder’s beliefs
Chiropractic has shown a small beneficial effect for the treatment of some lower back pain, but these results are controversial
What is it?
Chiropractic is an alternative therapy based on manipulation of muscles and bones, especially the spine. Its name derives from the Greek words chiro, meaning “hand”, and “praktikos”, meaning practice or practical.
Chiropractic was founded in the US in 1895 by David Palmer. He was a magnetic healer, practising a type of therapy similar to that of traditional bonesetters. Palmer claimed he had restored hearing in an almost completely deaf man by manipulating his spine, and subsequently developed the concept of “innate intelligence”, a primeval energy of divine origin that flows through the body.
In his view, misalignments of the spine (which he called vertebral subluxations) and other bones would prevent this energy from flowing freely, affecting the vibration of nerves connected to different organs and disturbing their functions. He claimed then that chiropractic could be used to treat any kind of illness. Palmer lacked formal medical training and was jailed for practising medicine without a licence.
The term vertebral subluxation, as coined by Palmer, has different meanings for conventional medicine and for chiropractic. In conventional medicine, a subluxation is a dislocation or displacement of a structure, including a vertebra, which can be seen in an X-ray. In contrast, a vertebral subluxation in the chiropractic sense is a misalignment of the spine which is not always visible in an X-ray, which causes alterations in nerves, causing disease. There is no evidence for the existence of such lesions or their ability to cause disease.
Vertebral subluxations are at the core of classic chiropractic training, but many modern chiropractors have distanced themselves from this concept, as well as from that of innate intelligence. They do not claim to be able to improve any kind of illness and base their practice on the treatment of muscle, joint and bone disorders. Other chiropractors, however, continue to believe in these concepts and claim to be able to treat any kind of disease through adjustments of vertebral subluxations.
Is it safe?
The safety of chiropractic treatment is controversial. Although most adverse side-effects of the therapy are mild and include soreness, stiffness, headache and fatigue, more serious effects have been reported. Stroke, paralysis and brain bleeding leading to coma and death have all been reported following chiropractic neck manipulation, although an indisputable link to the therapy has not been established. These serious adverse effects are also very rare. Chiropractic treatment is not recommended in patients suffering from bone cancer, rheumatoid arthritis or severe osteoporosis, among other disorders.
What does the evidence say?
Although a number of clinical studies have been carried out to assess the efficacy of chiropractic, many of them are of poor quality. In the case of chiropractic for the treatment of neck pain, for example, four trials have been carried out involving 409 patients. None of these studies were placebo controlled. Two of the studies compared the effect of chiropractic to that of exercise, although the beneficial effect of exercise for neck pain has not been demonstrated. Likewise, studies assessing the effect of chiropractic for autism spectrum disorder include three reports of individual cases and two studies involving a total of 43 patients, none of which were controlled or blinded, meaning patients knew if they were receiving treatment or not.
In the case of asthma, chiropractic therapy has been evaluated in two clinical trials involving 124 patients. Neither trial found significant differences between chiropractic therapy and sham (non-chiropractic) spinal manipulation on any of the clinical parameters measured. Similar results were obtained for studies on acute lower back pain, which are abundant: combined evidence from 20 trials involving 2,674 patients showed that chiropractic spinal manipulation was not more effective than sham manipulation when used alone or when combined with a treatment of a different kind.
Other conditions for which there is not enough good quality evidence to show beneficial effect of chiropractic are fibromyalgia, gastrointestinal disorders, upper extremity conditions (such as tennis elbow or carpal tunnel syndrome), sports injuries and dysmenorrhoea (period pain).
The effect of chiropractic on infantile colic has been evaluated by three clinical trials involving 325 children. Parents reported that chiropractic intervention reduced the number of hours crying per day, but they were not blinded as to whether their children were receiving chiropractic or not, so there is a high risk that the results of these studies are biased. Because the safety of chiropractic manipulation in very small children has not been assessed, and because infantile colic is not a dangerous condition and usually resolves on its own, chiropractic treatment is not recommended.
Chiropractic has shown a small beneficial effect for the treatment of some types of lower back pain, particularly chronic lower back pain, although these results are also controversial. Analysis of 26 clinical trials involving 6,070 patients has shown that there is a beneficial effect of chiropractic on lower back pain relief and functionality, but this effect is small, short-term and probably not clinically relevant. Another review including 39 clinical trials concluded that chiropractic is effective compared to sham treatment but not better than other types of treatment. Because of current issues with opiates for treatment of pain relief, the usefulness of chiropractic here would be important to establish.
Some evidence is available that suggests beneficial effects of chiropractic in the treatment of migraine and neck pain, but there need to be further studies providing good quality evidence before this type of treatment can be recommended.
In summary, there appears to be a small beneficial effect of chiropractic treatment for certain types of lower back pain, although the relevance of this effect is not clear. There is not enough good quality evidence to support the effectiveness of chiropractic treatment for any other disorder. Although serious adverse effects of chiropractic are very rare, more research is needed on the safety of this practice.