RESUMO
BACKGROUND: An automatic massage produces health improving effects. After a single automatic massage, patients admit a feeling of invigoration, and a sense of relaxation. Some quantitative characteristics of physical effects produced by the automatic massage on the body, including the work of a heart were unavailable at that moment. OBJECTIVE: This study aims to find a quantitative impact of periodic low frequency mechanical vibrations on the relative change in a heart stroke volume. MATERIAL AND METHODS: In this experimental study, the patients were exposed to the low frequency (12 Hz) planar mechanical vibrations. The blood pressures were measured before and after the automatic massage. Based on the measured values in the arterial blood pressure, a relative change in a stroke volume (SV) in patients was calculated. RESULTS: The increased systolic blood pressure was 6.3±2.0 mm Hg in women and 11.1±2.7 mm Hg in men. The increased diastolic pressure was 1.9±1.2 mm Hg in women, and 4.9±1.5 mm Hg in men. The minor increase in heart rate for women was 1.2±1.0 beats per minute, and 1.2±2.0 beats per minute for men. The assessment of stroke volume changes provided 9.6% and 7.1% increase during systole and diastole in male patients, respectively, and corresponding 6.7% and 4.7% increases for female patients. CONCLUSION: The results of our work confirmed an increase in the systolic and diastolic blood pressures under the influence of periodic mechanical vibration of low frequency. We believe that the registered increase in blood pressure is a proof of the increase in a stroke volume (SV).
RESUMO
BACKGROUND: Previous studies demonstrated a health improving effect in patients underwent an automatic vibratory massage taking 10 minutes. One of reasons that may explain a healing effect of the automatic massage is a stimulated increase in both blood circulation through vascular system and effective size of blood vessels. OBJECTIVE: This paper aims to quantify a contribution of the automatic mechanical massage of lower extremities into the observed reduction in arterial blood pressure and explain this effect. MATERIAL AND METHODS: In our experimental study, the lower extremities of male and female patients were exposed to low frequency (12 Hz) mechanical vibrations for 10 minutes and the change in systolic and diastolic arterial blood pressures before and after this procedure was measured. RESULTS: The experiments showed there is a reduction in systolic and diastolic arterial blood pressures after vibrational massage. There were corresponding 3.5±1.8 mmHg and 3.1±1.6 mm Hg arterial blood pressure reductions among men and 5.5±3.2 mm Hg and 2.2±1.2 mm Hg reductions among women. CONCLUSION: We explained this effect by increasing effective radius of blood vessels. Based on the Hagen-Poiseuille equation, we made estimates for the relative change in the effective radius of blood vessels. They gave the 0.7% and 1.3% increases in the effective radius of blood vessels in lower extremities in men during systole and diastole, respectively, and the corresponding 1.1% and 0.6% increases in the effective radius of blood vessels of lower extremities in women during the same periods.