Patient Concerns and Beliefs Related to Audible Popping Sound and the Effectiveness of Manipulation: Findings From an Online Survey



      The purpose of this study was to assess whether beliefs about the origin of the popping sound and the effects of thrust manipulation (TM) were in agreement with current scientific evidence and whether a practitioner's explanation could influence patient beliefs of theoretical mechanisms.


      A cross-sectional online survey was conducted in Italy from January 7, 2019 to April 20, 2019. The questionnaire was sent to 900 Italian adults through online recruitment, including people with and without a history of manipulation, such as given by physiotherapists, chiropractors, osteopaths, and manual medicine physicians to manage musculoskeletal disorders. The questionnaire consisted of 11 multiple-choice questions and could be completed within 15 weeks. The Likert scale was used to investigate participants' attitudes. Sex and previous experience of TM variables were evaluated using a Student's t-test; a 1-way F analysis of variance test was performed to evaluate age, educational qualification, and the professional who performed the TM.


      We retrieved 478 questionnaires, including 175 participants with no TM history and 303 with TM history. There were 31% of participants (n = 94) with a history of TM who reported they did not receive explanations regarding manipulation. The participants' beliefs mostly disagreed with the current hypotheses provided by the scientific literature on the theoretical mechanisms of popping sound (tribonucleation and cavitation). There were 9.9% (n = 30) of participants who answered “realignment of bone positional fault” to explain the mechanism behind TM. There was a high degree of agreement with the belief that the popping sound should be present for a successful TM (respectively, 2.8 standard deviation [SD; 1.2] and 2.6 SD [1.2] for TM+ and TM− participants). No statistically significant differences were found between participants with and without a history of TM.


      The participants in this study reported a belief that popping was related to effectiveness of TM. A high percentage of this sample had beliefs about TM mechanisms for the audible popping sound that were inconsistent with current literature. Beliefs were similar between groups, suggesting that instructions given by TM practitioners did not seem to be an influence on these patients’ beliefs.

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