A study in the Journal of Manipulative and Physiological Therapeutics (JMPT) may help relieve patient anxiety about the possibility of any kind of physical injury to their chest area despite the dynamic chest compression that occurs during adjustments and spinal manipulation.
While dynamic chest compression has been well studied in events such as motor vehicle collisions, chest compression forces have not been studied during chiropractic manipulation. In a study published online in May, in the JMPT, researchers quantified and analyzed the magnitude of chest compressions during typical as well as maximum chiropractic manipulation and have found them to be well under the threshold for injury.
“Results from this preliminary study showed that maximum chest compression during chiropractic manipulation of the thoracic spine is unlikely to result in injury,” according to lead investigator Associate Professor Brian D. Stemper, PhD, Department of Neurosurgery, Medical College of Wisconsin, Milwaukee. “We performed this study to get a better understanding of the force limits of chiropractic manipulation. This information may lead to safer manipulation procedures and help to decrease the possibility of adverse patient outcomes.”
In the first part of the study, Prof. Stemper and his co-investigators worked with two practicing doctors of chiropractic, each with a minimum of four years of doctoral training and at least seven years of health care experience. Using a crash test dummy, they measured the level of chest compression induced during “normal” chiropractic manipulation and during spinal manipulations in which the DCs exerted maximum effort. They performed simulated chiropractic manipulations on the test dummy at the mid back level (T7 to T8 vertebrae).
In the second part of the study, an instrumented mechanical device was used to apply and measure the forces necessary to induce chest compression in the test dummy. These forces were increased until injurious levels of force were reached. The likelihood of injury was assessed and classified using the Abbreviated Injury Scale (AIS), a useful classification system that has been correlated to injury thresholds during biomechanical experimentation.
In the present study, manipulations incorporating typical and maximum efforts by the chiropractors resulted in maximum chest compressions corresponding to minimal risk of AIS 1 level injuries.
As with all types of patient care, Prof. Stemper cautions that “individual patient characteristics including age, degeneration, and gender” should be taken into consideration.
SOURCE: “An Experimental Study of Chest Compression During Chiropractic Manipulation of the Thoracic Spine Using an Anthropomorphic Test Device” by Brian D. Stemper, PhD, et al. It will appear in the print edition of JMPT, Volume 34, Issue 5, June 2011.