HEADSTAND – MYTHS & FACTS
Headstand – There are many claims as to the benefits of headstand, but do they stand up to scrutiny? There does not appear to be any evidenced research to support the claims that appear over and over.
A claim that is seen often states the brain is infused with fresh blood which nourishes brain. If we examine the anatomy around the brain, we see it is protected by a blood brain barrier that supports the stable environment the brain needs. Too little or too much blood is harmful to the brain. If the volume of blood increases too much blood vessels may explode causing a stroke.
Baroreceptors located along the arteries in the neck and leading to the brain, detect changes in blood pressure. If they detect high blood-pressure signals are sent to lower the heart rate and relax arteries reducing pressure. If they detect low pressure, they send signals to increase heart rate and pressure.
It is often stated that the pituitary gland is enriched by fresh blood when inverting, which must be questioned if the brain is protected from fluctuations in pressure.
There are several contradictions for headstand, with menstruation often quoted in classroom setting. There is no scientific evidence to support that women should not invert when menstruating.
HEADSTAND – BENEFITS?
- Yoga inversions are also said to decompress the spine, although surely the pressure is just reversed.
- Headstands are often associated with a sense of calmness and are said to be superior to all other asanas. As mentioned before the body detects high blood pressure and tells the heart when to slow down. This could be said to be the reason why we may experience a sense of calm in inversions.
Another reason could be ‘reciprocal pressure’ which is when a muscle has pressure against it and tends to relax. When pressure is placed on the top of the head this could be the cause. We could create the same effect by pressing a hand on the top of the head.
Increased pressure equals increased volume?
An increase in a liquid or gas pressure does not necessarily mean that the volume increases as well. In the case of inversions this holds true as well. When one turns upside down there ‘may be’ a change in the arterial pressure leading to the brain.
- Gravity pulls our fluids earthwards and blood saturates the lower lungs
- Lower lung tissue becomes more compressed
- The air we breathe naturally moves into the more open alveoli
- Unless we take a good deep breath, we do not raise the ratio of air to blood in the lower lungs
- When we invert blood perfuses the wall ventilated upper lobes, ensuring more efficient gas exchange
- Inversions give the heart a rest
- Inversions improve venous return
REDUCING BLOOD PRESSURE?
When inverting the pressure differential across the body is reversed and blood floods the carotid arteries in the neck. It is believed that baroreceptors, mechanisms that calibrate blood flow to the brain, sense the increase in blood flow, and slow the flow thus reducing blood pressure and the heart rate (not proven scientifically).
VIPARITI KARANI leading to immortality
Vipariti Karani or inverted actions is a term used to describe a collection of inversions. It is when we practice these postures daily and with careful self-analysis that is possible to reach new levels in our yoga practice.
In the esoteric body it is said there is a nectar called amrit, which is stored at bindu and falls via lalana chakra to be consumed at agni. Amrit is the nectar of immortality and, by turning upside down it stems the flow.