Joint mobilization is a common physiotherapy technique used to treat musculoskeletal pain and dysfunction, especially following surgery. It involves stimulating the joints through passive movements and can be applied to joints in areas such as the ankle or spine.
While the technique has been shown to reduce pain in clinical studies, scientists are still trying to figure out how it works.
Using mouse models of postoperative pain, a team from Brazil, led by Dr. Adair Santos of the Federal University of Santa Catarina, showed for the first time that naturally occurring cannabinoids are involved with the pain-relieving effects of joint mobilization. Their findings were published online in the journal Neuroscience.
“This study represents the first direct demonstration of the role of the endocannabinoid system on the antihyperalgesic effect of ankle joint mobilization.”
By blocking cannabinoid pathways (CB1 and CB2 receptors), the researchers found that the pain-relieving effects of joint mobilization could be reversed. However, pain relief seemed to last longer when the mice were treated with a drug that stopped the breakdown of the body’s own cannabinoids.
According to the authors, the findings are consistent with data from human subjects which show that joint mobilization increases blood levels of anandamide – a natural cannabinoid that mimics the activity of THC.
While more research is necessary, the authors conclude that drugs which inhibit the breakdown of cannabinoids like anandamide could be used to enhance the benefits of joint mobilization in the future.
The study received funding from Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Fundação de de Amparo à Pesquisa e Inovação do Estado de Santa Catarina (FAPESC), and Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), Brazil