The effect of cervical and thoracic spinal manipulations on blood pressure in normotensive males

Abstract

The Effect of Cervical and Thoracic Spinal Manipulations on Blood Pressure in Normotensive Males. BACKGROUND A distinguishing feature of chiropractic is manipulation that is a load delivered by hand, to specific tissues (usually a short lever bony prominence) with therapeutic intent. Chiropractic spinal manipulation results in somatovisceral reflexes, which can affect the cardiovascular system and thereby reduce blood pressure. Areas of the spine known to cause such effects are the upper cervical region and the upper thoracic region. Increased blood pressure/hypertension is a global disorder. The incidence is increasing and leads to complications of cardiovasular disease and cerebral vascular accidents OBJECTIVES The objectives of the study were to determine whether spinal manipulation evokes somatovisceral reflexes and causes a reduction in blood pressure following an atlanto-axial (C0/C1), and Thoracic segments one to five manipulations (T1-T5). METHODS Forty, asymptomatic, normotensive males between the ages of 20 – 35 years of age participated in the study. All subjects underwent four consecutive days of intervention. Day one was sham laser. Day two was C0/C1 spinal manipulation. Day three was T1-T5 thoracic manipulation. Day four was a combination of C0/C1 and T1-T5 spinal manipulations. RESULTS The results of this study suggest that blood pressure decreases following a cervical or a thoracic manipulation, however a combination of the manipulations does not have a significant cumulative effect on the reduction of blood pressure. iv CONCLUSIONS Somatovisceral reflexes are evoked following a spinal manipulation, causing a reduction in blood pressure after an upper cervical or upper thoracic manipulation. Neurophysiological effects occurring as a result of spinal manipulation may inhibit or excite somatosomatic reflexes, which changes heart rate and blood pressure.