I believe respecting yoga tradition and conventions is usually a good thing but sometimes the conventions that we are supposed to follow have no foundation in modern science. That’s when someone like me gets a mind-bend. Should I ignore my rational side and go with the flow or is it OK to question and be critical, maybe in the end reject what I am asked to do?
I usually try to find a solid, realistic explanation and if/when I fail to do so I change my perspective on the subject. One example of such situation is the question of chakras. Science tells us that we don’t really have nadis (channels) where Prana (i.e. the life energy) flows or chakras where these nadis intersect. Therefore I choose not to take in the physical aspects of the whole chakra philosophy. Albeit, I do think that the content attributed to each chakra has a real reflection in human life, thus I see chakras as a general framework or a general guide to try to figure the person I am and the way I feel at a given time.
Another convention I choose to ignore is skipping the inversions during my period because after some research I found no evidence that inverting during menstrual cycle has bad consequences for your health. Frankly, I find it more difficult to go into a headstand because I usually have very balance during my period. For the same reason I would usually do lighter versions of balancing postures, too. But, I still will want to do the inversions because I know I feel calmer afterwards and my bloated feet and legs can take a break.
Yoga is a thousand year old tradition and practice, it would be illogical for us, modern yogis to accept everything in yoga tradition as it is. Lack of critism is the worst enemy of progress in any area. I love yoga but I don’t want to do things that I find no sense in just because…
Here is a link to a short article on Slate Magazine about the (non-existant) medical relationship between inversions and menstrual cycle:
Ebru's Yoga Blog 