I love science. Not that I want to be a scientist … but I am pleased with the scientific methods and their results. Also I have a quite skeptical personality, so I try not to jump to conclusions quickly as I have learned from my mistakes about it. This is critically a question that the reality can be very controversial in the community of Yoga.
For example: the renowned book ‘Light on Yoga, BKS Lyengar,’ is commonly regarded as a modern ‘bible’ regarding yoga poses.
But look at this … In Salabhasana posture (the lobster, which appears in the photo), the book mentioned as some of the effects of the position in the following words’
“As the spine is stretched back, it becomes elastic and posture relieves pain in the lumbar and sacral regions. In my experience, people who suffer from herniated discs have benefited by the regular practice of this asana without resorting to forced rest or surgery. The bladder and prostate also benefit from exercise and stay healthy.”
Actually the spine is made of bones which do not stretch. And muscles do not stretch the spine in extension, but that contract (or activated concentrically if you want to be even more accurate). Although we could say that the front region of the spine can make range of motion that is very different from saying that the column becomes elastic.
In case of herniated discs, although many people with this type of extension can help in some cases may aggravate the pain. If you have a good yoga therapist (or a good therapist), you can find out without hurting you.
Finally, and perhaps most important in this conversation: There is no evidence that the prostate or bladder benefit from this approach. You may wonder “Where do yoga teachers get this information from?”
Part is through their ‘personal anecdotes’, experimenting on their own body and part in what they learn from their teachers or books like Lyengar. The other part might be what every teacher learns as he/she teaches his/her students.
But how do we know that the deductions and observations are correct?
We can not know. If anything science has taught us, it is that what works for you will not necessarily work for others. Even if some posture can help 20 people in the experience of a teacher, many variables could have doctored the results. That is why even when a researcher uses the scientific method, after the study, it is criticized by his/her colleagues as they try to replicate the results to verify the methodology.
It is the task of yoga teachers to separate what they know from what they believe and this distinction should be passed on to the students.