Is the Spinal Manipulation Pop Necessary?

Impact of audible pops associated with spinal manipulation on perceived pain: a systematic review If a joint manipulation is performed but nobody hears a sound, did the manipulation work? This question has been asked for decades and the answer remains the same. The current body of evidence shows there is no difference in outcomes between audible and silent joint manipulations. There are many theories supporting the importance of the audible pop, including clinician and patient beliefs and the muscle reflex response, but the literature has not supported these theories to date. This review was limited to five studies, highlighting the scarcity of research on this topic. All five studies concluded that there is no statistically significant association between audible pop and perceived pain. This doesn't mean an audible pop will never be important, as some patients may associate the pop with success. Clinicians may re-attempt a manipulation if they fail to achieve an audible pop or may appear frustrated if they don't achieve a pop. The differences in outcomes are more attributed to belief effects rather than a local physiologic mechanism.