the science of yoga

I'm a geek and embrace the science supporting yoga and share the most interesting tidbits with my students. It's too fascinating not to and since the more esoteric aspects of yoga has less potential to resonate with everyone, maybe science will.

I'm reading the Science of Yoga by William Broad, the same authored who penned the NY Times article, How yoga can wreck your body. Among the myriad of risks and rewards related to yoga, the risk associated with neck strain is most relevant to this posting. I always encourage my students to move with ease while maintaining the natural curves in the cervical (neck) and lumbar (lower back) spine. Looking around to see what the teacher or fellow yogis are doing distorts these natural curves , as well as optimal ranges of movement. The body can't release tension if we're creating it. It's a silly ego driven notion which doesn't consider whether or not the body is ready.

Some neurologists would argue that contorting (and holding) the neck for extended periods of time has the potential for more deleterious health risks such as strokes and impaired brain function. There are two vertebral arteries that run along the cervical spine and into the brain stem. They supply blood to the parts of the brain that are responsible for respiration, converting pulses into images and muscle coordination. Persistent or inappropriate movement in the cervical spine could pinch these arteries and reduce the blood flow to the brain.  For example, think about the position of your head and neck in Bjuangasana (cobra pose). (NB Cobra pose is a back bending pose and as such the curve in the lumbar is deeper than neutral.) The image below is merely demonstrating different ranges of movement and remember what is appropriate for one yogi isn't appropriate for another other.

Another potential case of causing damage to the neck and consequently brain function can occur by moving into shoulder stand (Sarvangasana) or plow (Halasana). In this case, prolonged resting or moving inappropriately into these poses can damage or crush the cervical vertebrate thereby pinching the vertebral arteries or cause paralysis.

Remember these are extreme cases of the potential risks of an over-zealous practice or of moving inappropriately. My purpose was to share an interesting fact about human physiology and not to scare anyone. Practice with ahmisa (non violence) move within your optimal range of movement as you nourish a sense or relaxation, and ensure that you maximize the wonderfully healthful benefits of a safe yoga practice.

Namaste
Nancy-Anne