The manipulative therapies: osteopathy and chiropractic

British Medical Journal, Oct 30, 1999 by Andrew Vickers, Catherine Zollman

Research evidence

There is considerable evidence from randomised controlled trials of the effectiveness of spinal manipulation for back and neck pain. Although this evidence is largely positive, it has been criticised for failing to exclude non-specific effects of treatment.

In the best known UK trial 741 patients with low back pain were randomised to chiropractic or hospital outpatient care. In both groups the treating practitioners were free to treat patients as they saw fit. The authors concluded that "chiropractic almost certainly confers worthwhile, long term benefit" However, a recent systematic review of this and similar trials highlights methodological weaknesses, such as the fact that commonly used outcome measures such as pain and disability scores are assessed by patients and therefore unblinded.

In one trial that did involve blinded assessment of outcome, patients with back or neck pain were randomised to routine general practitioner care, placebo (deactivated heat treatment), physiotherapy, or manipulation. Physiotherapy and manipulation were superior to placebo and general practitioner care after six weeks, and manipulation was superior to physiotherapy atone year follow up.

In addition to effects on back and neck pain, randomised trials have also indicated that manipulative treatment is beneficial for headache, including migraine. However, the number of studies is small, so further work to confirm these results is needed. There is little or no reliable evidence of beneficial effects for many of the other musculoskeletal conditions that are commonly treated.

Apart from dysmenorrhoea, for which a small number of trials have shown a positive effect, current evidence suggests that manipulative therapy is not of benefit for problems related to smooth muscles or viscera, such as asthma and hypertension.

There has been little research on cranial osteopathy or McTimoney chiropractic.

Safety of osteopathy and chiropractic

The most important potential adverse effects of osteopathy and chiropractic are stroke and spinal cord injury after cervical manipulation. Estimates of such severe adverse events vary widely, ranging from 1 in 20 000 patients undergoing cervical manipulation to 1 per million procedures. In recent years the osteopathic and chiropractic professions have shown greater appreciation of the risks of cervical manipulation, and it is possible that improved practice is leading to a reduction in the rate of severe complications.

More common adverse effects (25-50% of all patients) are mild pain or discomfort at the site of manipulation, slight headache, and fatigue; 75% or more of such complaints resolve within 24 hours. Contraindications to various manipulative techniques have been developed by the appropriate professional bodies, and practitioners are trained to screen patients and assess individual risk factors. Even when some techniques, such as high velocity thrusts, are contraindicated, other manipulative treatments may be safe.

Practitioners