Clinical trials of spinal manipulation: a critical appraisal and review of the literature.

The literature has produced sufficient evidence to suggest that spinal manipulation may be more effective than standard medical care in the management of painful musculoskeletal conditions; most notably that of low back pain. However, much of the research has been severely criticized because of poor methodological design characteristics, the incorporation of systematic bias and the increased likelihood of making serious beta errors. This review identifies the essential components which distinguish 'good' clinical research and critically appraises the nearly four dozen clinical trials of spinal manipulation which have been published to date. It was observed that only the randomized control clinical trials demonstrated sufficient rigor to adequately control the data collection and analysis but agreement about the clinically relevant outcomes of manipulative therapy still have not been consistently demonstrated.