As we continue to get through the colder, darker and more sedative months of winter, inversions and backbends are a fantastic and holistic way to combat the symptoms of SAD (seasonal affective disorder), exhale out the stress of the holidays and warm up the body and soul. Below is a little introduction to the physical and neurobiological mechanics of backbends and inversions. I also offer some insight and instruction on how one can correctly execute these great mood enhancing poses that not only help to relieve lethargy but are also great for releasing neck and shoulder tension.
The nervous system, back bends and inversions:
One cannot discuss the nervous system without introducing the Vagus Nerve. This is a fascinating nerve that is linked to everything from digestion to depression. Dr. Levine and Dr. Kolk in their research hypothesize that there is a direct connection with the poor functioning of the vagus nerve and its associated organs with anxiety and depression. Simply put, the hypothesis is that anxiety has it´s root in an overactive fight/flight response and depression is then the result of the frustrated fight/flight response. In other words, when the nervous system perceives that there is no way out of a perceived threat, the biological defense response is a kind system shut-down that results in what researchers call ´freeze´ and what would be experienced on the emotional level as depression.
Levine and Kolk argue that these sensations of stress, anxiety and depression occur first in the body and are then interpreted in the brain. The primary path of this communication from body to brain is the vagus nerve. There is more and more literature discussing the importance of a good ´vagal tone´ to maintain both mental and physical health. In fact, pharmaceutical giants Glaxo-Smith-Kline are trying to make profit out of this fact by investing over 50 million dollars in researching a device that would provide vagus nerve stimulation (Medicine Beyond, p. 235). Lucky for humanity, Vagus nerve stimulation is something that Yoga provides naturally and free.
What is the Vagus Nerve?
Vagus is Latin for ´to wander´ and that is exactly what this nerve does. It starts up behind the ear moves down the neck and continues to spread out it´s tentacles along the chest, around the heart and into the gut. 70-80% of the information that is passed along the vagus nerve moves from the bottom up and only 20-30% of it moves from the top down. This is why some people say the second brain is in the gut. All those sensations that are experienced in the gut (which has as many neurons as a cat´s brain) and along the organs connected to the Vagus Nerve are sent up to the brain to be analyzed and interpreted by the pre-frontal cortex, language centers and amygdala. That means working with the vagus nerve and the organs connected to it can modify messages sent to the brain about sensations that are experienced in the body.
Cuddy, Kolk, Levine and other renown researchers like Dr. Steve porges are demonstrating how direct work with the body influences our energy levels, sexual desire, sleep patterns and digestion…and working with the body to control the mind and increase quality of life IS precisely the theory behind the practices and postures of Hatha Yoga.
Poses for Vagus Nerve Tone: Examples and why they work
Due to the physical form of these poses backbends work directly with the vagus nerve. Backbends, or back extensions as they are also known, work by opening and toning the front of the belly, chest, sternum and throat which, as mentioned earlier is home to that wandering vagus nerve. Via breath, pressure, stretching and by holding back bends CORRECTLY while breathing into the pose the organs associated with the vagus nerve and the nerve itself is activated, toned and strengthened. A well ´toned´ vagus nerve and the attached organs means that the brain receives biological signals of relaxation such as a regulated digestive tract, slower heart rate and deeper breath. It signals to the brain, via the Vagus Nerve, that all is well and there is no need for fighting, running way or freezing up.
It is important that when practicing backbends that one take great care around the lumbar spine. The most common mistake in these poses is to clench the buttocks-which can result in compressing the lumbar spine. Also, when going up into poses like bridge (urdva danurasa), compression of the lumbar occurs when one pushes straight up through the public bone or belly button rather than lengthening the lumbar and lifting through the sternum. My advice in all back bends is, to think about internal rotation of the thigh bone and activation of the abductors…the muscles on the inside of the thighs. This action will automatically open the space around the lumbar and activate the abdominals which need to be strong to protect the lumbar. Always start slow and gain real awareness of what the space around the lumbar, stretch across the chest and strength in the abdominals FEELS like. Look for the correct sensation, not just the correction formation.
For thousands of years human beings have practiced inversions and now in various physical therapy clinics, props like inversion tables are common.
The ´Yoga Form´ mechanics of inversions are fantastic not only for decompressing the entire spine, which is of course has its effect on the entire nervous system both posteriorly (along the spinal cord) and anteriorly (vagus nerve) but is also great for increasing lung capacity, activating digestive organs, strengthening the immune system (by helping to activate the lymphatic system), regulating hormone release and increasing the production of all those feel good neurotransmitters like dopamine and serotonin.
All this neuro-biological activity that occurs during inversions results an overall more balanced state of emotional, mental and physical well-being.
Just like with back extensions, one must be very
aware of doing these poses correctly
to avoid causing damage to the cervical AND lumbar spine. The most common mistake in inversions is putting too much pressure on the neck and not bringing the weight of the body into the shoulder girdle. Again, look for the correct sensation, not just the correction formation. One should feel activation in the triceps, the dorsal spine and the pectorals NOT the neck or lumbar spine. Think about pushing the shoulder blades up towards the hips, the elbows and wrists towards the ground and maintain the aforementioned rotation of the thighs, like you would in a back extension, to keep the core active and the lumbar spine protected.
Every yoga pose (asana) should be done with awareness and with careful internal observation-after all asana means ´seat of awareness´ – and this awareness even more important for backbends and inversions.