yoga seeds #12 – Valsalva manoeuvre

Here’s a wonderful term that you can casually drop at your next social get-together to impress friends and relatives alike! As sophisticated as it sounds, this action is what makes the throaty grunt that sometimes accompanies a big physical effort like lifting or pushing a heavy load or even a move during yoga class… Achtung! It’s not the best way to rise up to a physical challenge. It’s not a matter of aesthetics but pure physics. Here’s an explanation.

The organs in the abdomen are surrounded by liquid in a closed hydraulic system. If you press on one part of it, the pressure will be transmitted through the rest of the region, like in a closed toothpaste tube. On the other hand, the thorax is a pneumatic system filled with air with an opening at the throat. When the glottis is open, the system is at atmospheric pressure, but if we inhale, close the glottis and use the intercostal and abdominal muscles to press in (the relaxed diaphragm will transmit the “tooth-paste tube” pressure from the abdomen to the thorax), we can increase that pressure. Why would we want to increase the pressure in the trunk? To support the very mobile and loaded lumbar region by creating a taut unit that will not bend and to spread the vertebrae apart and relieve strain on the discs. The thing is that, when we do a Valsalva manoeuvre, the increased pressure in the thorax immediately increases our blood pressure. How can we get around this? Use only the abdominal pneumatic system by pushing down your diaphragm as if you were inhaling and

keep your glottis open while you gather your abdominals in and your pelvic floor up.

This not only avoids a peak in blood pressure, but also strengthens your core muscles (respiratory diaphragm, transversus abdomini and pelvic diaphragm in this case). Of course, resort to a Valsalva Manoeuvre if you need to rather than hurt yourself but, otherwise, keep the air flowing and your core toning!

Thanks to all my students at Yoga Hub Berlin, who inspire me with their practice.

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yoga seeds #9 – The ups and downs of headstand

*Contains more than the usual daily serving of anatomic and physiological references. 100% useable. Does not contain traces of (being) nuts.

Inversions in general and headstand (shirshasana) in particular are controversial in the yoga community. On one extreme there are those who say they are the most important poses in yoga. On the other, there are others who see only dangers and no benefits and exclude them from the practice altogether. In order to find our place along this continuum I think it’s important to put aside unsubstantiated claims like “it purifies the blood” or “it cures diseases” and look at some facts:

Shoulder girdle

  • When we are standing up, the connection taking our weight to the ground is through our two hips, which are very stable joints. However, in headstand this connection is made through the shoulder girdle. This has in fact four joints on each side, providing greater mobility and less stability. In order to do headstand, we need to develop a strength and awareness for balance in our shoulder joint that we do not practice at all in our everyday life.

Neck

  • The spine is designed to take more weight at the bottom than at the top. Inversions challenge this logic and therefore call for precaution. Even if the vertebrae themselves can take the weight, bringing the spine out its natural curves with a heavy load on top can expose the intervertebral discs to injury. Thus, it is necessary to have developed precise propioception and strength to preserve the spine’s natural curves as we go upside down. In particular, any cervical discs that are already damaged will suffer.
  • On the other hand, moderate mechanical loading strenghtens all spinal tissues, including the discs.

Return circulation

  • Both lymph and venous blood return are supported in inverted positions. This allows for a better exchange of nutrients and waste products between cells and capillaries.

Blood pressure

  • In inversions the heart needs to pump harder, against gravity, to get the blood all the way around the body. This is counterindicated for people with high blood pressure, irrespective of whether they are on medication.
  • Increased pressure stimulates the very sensitive baroreceptors in the arteries supplying the head with blood. The result of this is a reflex decrease in blood pressure (however, this is not a cure for high blood pressure).

Diaphragm

  • The weight of the abdominal content encourages fuller exhalation and, therefore, renewal of the air reserve in the lungs (that is, better oxygenation) and stretching of the diaphragm.
  • Diaphragmatic breathing is encouraged, because chest breathing is restricted by the muscles required to hold the asana. Also, the weight of the abdominal contents on the diaphragm provide resistance, that is, extra exercise, that strengthens the diaphragm.

Eyes

  • The pressure in the head and, therefore, inside the eyeballs, increases. Increased intraocular pressure is one of the factors that can lead to glaucoma. There is also a relationship, although much weaker, to retinal detachment.

Mind

  • It is difficult to be distracted from the here and now when we are in a challenging position like this. However, it is easy to be distracted from the experience of how our body is doing and be carried away with the idea of making the asana ours.

Headstand is one of the iconic poses of yoga. It can be very seductive as a sign of progress, a measure of comparison and a trophy of accomplishment. We mustn’t forget, though, that hatha yoga is not merely a catalogue of body shapes (see post #7 – Progress). This practice is physical and can definitely open up more awareness, flexibility, strength and balance in our bodies. However, not only that. It can also open up more awareness (about what we need and can, as opposed to what we want), flexibility (to let go of ideas of what we should be doing), strength (to stay true to our course) and balance (to find middle paths that honour every single aspect of our beings). Full headstand is not for everyone. However, all the component parts that make it up can be made available to “every body” by means of alternatives or adaptations. The most important thing is not whether we do headstand or not, but to go for what serves us best and do away with the rest.

Thanks to all my students at Yoga Hub Berlin, who inspire me with their practice.