The use of RCT's in manual therapy--are we trying to fit a round peg into a square hole?

Evidence based practice has been defined as "the explicit, conscientious and judicious attempt to find the best possible available research evidence to assist the health professionals to make the best decision for their individual clients." (Sackett et al., 1996). In clinical manual therapy practice, this involves integrating research evidence with clinical experience and patient values. Currently randomised controlled trials are considered the highest level of research design in terms of strength of the evidence provided, due to the methodological control of potential sources of bias. However, the mechanisms that ensure internal validity of an RCT, i.e. randomisation, and intervention standardisation, threaten the generalisibility, and therefore relevance of the evidence to manual therapy. Manual therapy represents a complex intervention and therapists need to review the notion of 'research evidence', in the context of the clinical practice of manual therapy. Reviewing the construct of what constitutes an intervention, increasing post-hoc analysis of subject sub groupings and revisiting 'lower levels' of research design are all suggested as possible approaches.