Drs. Childs and Flynn erroneously concluded that our review states that spinal manipulative therapy does not work. The data we reported show that spinal manipulative therapy is more effective than either a sham manipulation or ineffective therapies. The data do not show that spinal manipulative therapy is more or less efficacious than other advocated therapies. Dr. Shapiro erroneously concluded that spinal manipulative therapy as defined in our report was "thrusting or high-velocity, low-amplitude technique" and that "in reality, manipulation is an eclectic group of techniques." In contrast, we specifically acknowledged the heterogeneity of techniques that are considered manipulative therapy and included in our review studies that specifically excluded high-velocity techniques. We performed sensitivity analyses on our pooled results by separating them into the studies that specifically used high-velocity techniques versus all others; we did not find any difference in our results. Last, Drs. Childs and Flynn and Dr. Shapiro adhere to the common belief that there is an identifiable subgroup of patients with back pain who will have a very good response to spinal manipulative therapy but no other therapy. The clinical prediction rule cited by Drs. Childs and Flynn was developed from a cohort of 71 patients, all of whom received spinal manipulation; therefore, it is impossible from these data to conclude anything about the response of these patients to spinal manipulative therapy versus any other therapy or even no therapy. Of note, the most strongly predictive variable in this clinical prediction rule was duration of pain, which most strongly predicts recovery even in the absence of treatment. We know of no data that will allow the clinician to identify in advance those patients with back pain who will respond better to spinal manipulative therapy than to other active therapies, or even that such a population of patients exists. If it does, the data we reported suggest that it must be small.