Spinal manipulation therapy is a widely-accepted method for treating back pain, neck pain, and headaches. Although previous studies have pointed to the safety of chiropractic neck adjustments, there has been some concern about the effect of the forces applied during spinal manipulation of the neck. It has been argued that there is the possibility of damaging the internal carotid artery (ICA) by such force. Previously, little was known about the strains sustained by the ICA during spinal manipulation therapy. In a recent study, researchers sought to examine the mechanics of the ICA during neck manipulation to determine whether spinal manipulation causes strains in excess of those experienced during normal everyday movements.
The researchers measured strains applied to the internal carotid artery (ICA) during neck spinal manipulation treatments. Peak and average ICA strains were measured in 6 cadaver spines during cervical spinal manipulation performed by chiropractic doctors. These number were compared with the corresponding strain experienced during diagnostic testing of the head and neck to simulate normal everyday movements.
The researchers found that ICA strains were no different during chiropractic manipulation of the neck than during normal everyday movements. Therefore, cervical spinal manipulation performed by trained chiropractors does not appear to place undue strain on the ICA.
Earlier research has also demonstrated the safety of chiropractic neck adjustments. In an extensive literature review from the medical journal Spine, researchers analyzed data from 28,807 chiropractic patients receiving a total of 50, 276 adjustments of the cervical spine. Among the thousands of adjustments made, the only negative side effect reported was temporary, mild dizziness; no serious side effects were reported.
Herzog W, Tang C, Leonard T. Internal Carotid Artery Strains During High-Speed, Low-Amplitude Spinal Manipulations of the Neck. Journal of Manipulative and Physiological Therapeutics 2012; pii: S0161-4754(12)00156-X. doi: 10.1016/j.jmpt.2012.09.005.