Study: ( Earth Magnetic Field ) ... the Effect of Head Direction in                            Shava Asana on Heart Rate and Blood Pressure

Indian culture stresses the importance of direction during the performance of daily activities. Some yoga teachers prescribe that the yogic relaxation and polarity practices must be done while lying with the head towards the North in order to align oneself with the earth magnetic field.

There is some evidence that the earth magnetic field influences physiological functions. Hence, this study was undertaken to determine if head direction has any effect on heart rate and blood pressure during supine rest (i.e. lying in shavasana).

43 normal, healthy school children were recruited and randomly assigned to lie with their head toward one of the four cardinal directions (North, South, East, or West) on four different days. Heart rate and blood pressure were recorded after five minutes of supine rest.

Heart rate was lowest when the head was toward the North, and highest toward the South, the difference being statistically significant. Systolic pressure was lowest toward the North as well, and significantly higher toward the West.

Lying supine with the head toward the North had the lowest rate-pressure-product, compared to the West.

This study demonstrates that lying supine with the head toward different directions does have and effect on heart rate and blood pressure. Further studies in different age groups and in hypersensitive patients may help in understanding the mechanisms and implications of this phenomenon (i.e. the influence of the earths magnetic field on physiological functions).