Does the popping sound with SMT matter for pain outcomes?
When you adjust a patient, do you think the popping sound is necessary to achieve a desired clinical outcome regarding pain? This week’s Review looks at the evidence in this space…
Spinal pain is very common worldwide and can have a significant negative effect on the lives of those affected as well as increased costs to society. Many people with spinal pain seek treatment, with about 75% of spinal pain patients consulting either a chiropractor, physical therapist or osteopath. Such clinicians commonly provide spinal manipulative therapy (SMT) and/or spinal mobilization as treatment options, which are recommended as treatment options in several practice guidelines for the management of both low back pain (LBP) and neck pain.
Most chiropractic patients are accustomed to hearing a popping or cracking sound associated with SMT and the clinician delivering SMT may associate this sound with the perception of a successful intervention. In fact, some clinicians apply another thrust (or multiple additional thrusts) when the sound does not occur.
Tribonucleation is a term that describes the process which causes a joint to generate a cracking sound and occurs when sufficient distraction force overcomes the viscous attraction or adhesive forces between opposing joint surfaces. Rapid separation of the articulation occurs with the resulting drop in synovial pressure allowing dissolved gas to come out of solution to form a cavity within the joint.
It is commonly understood that the objective of SMT is to restore joint function and mobility, although how this is achieved and whether SMT is responsible for proven decreases in pain and improvements in function are undetermined. It has been suggested that personal interaction and therapeutic touch by the clinician produces psychological reassurance for the patient. However, the clinical relevance of an audible pop (AP), though inextricably associated with SMT, is currently unknown.
Hence, the objective of this review was to assess and update the evidence concerning the role of the AP in producing therapeutic benefits associated with SMT, specifically if the AP plays a role in decreasing pain perception.
RESEARCH REVIEW: “Impact of Audible Pops on Perceived Pain After Spinal Manipulation”
This paper was published in Chiropractic & Manual Therapies (2022) and this Review is posted in Spinal Manipulation – Mechanisms of Action and the 2022 Archive.