Table 1 summarizes many of the studies cited in this article. Can we specifically answer the question, "Does manipulation effectively treat musculoskeletal disorders and arthritis?" It is apparent that many individuals make decisions to see therapists who use manual techniques for pain relief and improved function even though few third-party payers cover such treatments. If this question could unequivocally be answered in the affirmative, these treatments would likely be reimbursed by the payers. The studies noted in Table 1 show mixed results for several conditions. Each study has its strengths and weaknesses, but the most powerful ones indicate that manual techniques are beneficial for back and neck pain when compared with no treatment or "placebo." Comparative studies against other techniques such as physical therapy, education, or exercise do not show a clear superiority for manual therapy, however. Thus, one would have to conclude that these techniques have usefulness, primarily as adjuncts to a comprehensive treatment program. Particularly, manual techniques are useful for painful conditions as a means to break the pain cycle and increase tolerance of exercise and other educational approaches. Although clinical trials do provide important information, they do not provide information on the mechanism by which the therapy assists in the healing process. Further work is needed to understand the mechanism by which manipulation affects pain and motion. Such research should clarify the discrepancies reported in the clinical trials and provide better designs for future studies.