A2002clinical practice guideline reported the true risk from manipulation is not known and that the greatest reported estimate of risk in the literature for irreversible injury is 1 in 20,000.11 Uncertainty is associated with the reported estimates due to small sample sizes and the quality of the studies reviewed. Di Fabio12 concluded that the risk may be minimized, but not entirely eliminated, with the use of mobilization instead of manipulation. To date, however, there is no empirical evidence that the risk is influenced by the type of technique.13