Head over Heels
When one comes down from Headstand, one often feels clearer and calmer. The common assumption is that Headstand floods the brain with freshly oxygenated blood, and the brain is refreshed. Is there such a thing as too much blood to the brain? Dr. B. Ramamurthi, a neuroscientist based in India, has shown that the brain is protected from an influx of blood that would overwhelm its delicate structures, and that when a reasonably healthy individual inverts, there is usually no excessive influx in the blood vessels of the brain. Intense pressure in the head or bloodshot eyes, however, call for a modified practice. A study by Dr. F. Chandra, well known in Europe for her lectures on the physiological and psychological effects of yoga, posits that Headstand could effect a base-line opening of blood vessels, making them more efficient at dilating and constricting to efficiently shunt blood to the active areas of the brain.
Inversions may also affect the movements of cerebrospinal fluid (CSF), the juice of the central nervous system which flows from the brain to the spinal cord. The top of the skull receives intense pressure in Headstand, which, when properly done, may promote elasticity in the cranial bones, thus stimulating the production of CSF in the ventricles of the brain.
The effect of inversions on the intricate endocrine system, the body's glandular system of hormone delivery, has been much touted, but is perhaps the least understood: Shoulderstand is widely recommended for menopausal and perimenopausal women because it is assumed that it stimulates the thyroid and parathyroid glands, which secrete hormones that regulate one's metabolism. This has not been clinically proven, but Payne assumes that inverting places these glands, located in the upper chest, in a "general bath of blood," thus increasing their efficiency.
In Headstand, the pineal and pituitary glands (which sit behind the eyes in the center of the skull) are upended 180 degrees, directly over the fontanelle. We know that the pineal and pituitary glands are responsible for growth and sex hormones. We do not know what reversing these glands in the field of gravity does. Could this, however, be the dripping amrita of the ancient yogis—might they have sensed the slow release of hormones from the cranial vault and used inversions to stem or stimulate the release, promoting health and impeding aging?
To Invert or Not to Invert?
B., an osteopathic therapist, spoke to me only on the condition of anonymity. He has worked with a few long-term yoga practitioners in their 50s who came to him with chronic pain or impaired mobility in their necks. They have bodies of 30-year-olds, but their necks are so stiff and pain-ridden from the yoga inversions, they are like the necks of 60-year-olds, he says. Over his 20-plus years of practice, B. has seen many clients who, already vulnerable in the upper spine from cervical degeneration, whiplash, an old injury, or misalignment, unknowingly exacerbate the situation by inverting in yoga class.
He explains that the brachial plexus, a key network of nerves that exit the spine from between the lower cervical vertebrae and upper thoracic (C5-8 and T1), enervates the entire upper extremities and shoulder region. Headstand and Shoulderstand place tremendous compressive force on the upper spine, which, for those who are vulnerable, can cause nerve irritation and compression to the brachial plexus, as well as "general thoracic outlet syndrome," which may compromise blood circulation and manifest as numbness in the arms and hands.
Arthur Kilmurray, director of Mystic River Yoga Studio in Medford, Massachusetts, has experiences that support B.'s claims. He began studying Iyengar Yoga in the late 1970s and was doing long inversions within four to five years. But by 1988, Shoulderstand had become impossible: He felt as if his head would explode when up in the pose. Kilmurray assumes this stems from a football injury at age 21, exacerbated by long inversions. Even now, although he feels no pain, chiropractors are astounded by the lack of range of motion in his neck. Kilmurray does not currently practice Headstand or teach inversions, and teaches his students to "develop sensitivity to the breath, prana, and fluidity of the inner body" before moving towards the longer inversions and more advanced poses.
Inversions are not for everyone. Even if you are inverting consistently now, there will be times when the practice is inappropriate. In the face of this "failure" to invert, it may be helpful to recall the yogic tenets of ahimsa, nonviolence or compassion, and svadhyaya. We practice yoga to decrease suffering and develop our capacity to be fully present in our lives. Why persist in practicing Headstand and Shoulderstand if it causes you pain? Restorative poses such as Viparita Karani (Legs-Up-The-Wall Pose) and a supported Setu Bandha (Bridge Pose) will give you some of the benefits of Headstand and Shoulderstand, without taxing the cervical spine.
If you are new to yoga, take your time before inverting—a year is not too long. Work closely with an observant and knowledgeable teacher. Attend class regularly. Learn the fundamentals: Find the extension of the spine first in Adho Mukha Svanasana (Downward-Facing Dog); open the shoulders with Adho Mukha Vrksasana (Handstand), Pincha Mayurasana (Forearm Balance), and Vasisthasana (Side Plank Pose); and develop balance, clarity, and strength with the standing poses.
Studying the Yoga Sutra and Bhagavad Gita will help you structure a yoga practice that is balanced and wise. Practicing alone will help you purge the urge to perform your asanas for others and cultivate a deeper understanding of your body and its rhythms so that you can practice in ways that respond to your needs. With mindfulness, even a beginner can practice inversions without injury.
If you already invert, ask yourself how you do it. Do you use muscle to stay up, as Peter did? How much do you observe yourself in the pose, focusing on your alignment? If you wish to work towards longer poses, by all means do so. But do so intelligently, and be willing to progress slowly if you want a healthy neck into your dotage. Observe the subtle changes in your neck and throat, and watch your breath. Stay up for short periods of time first—a minute or two. Back up on occasion. Always come down if there is pain.
After the injury, Peter has changed his practice. He now sits daily, attends a weekly restorative yoga class, and does shorter inversions. He has realized that intention and focus are more important than throwing himself through the poses. Practiced without wisdom and compassion, inversions can lead to injury. But at their best, these poses sing up the spine and the body hums with joy. Headstand and Shoulderstand are known as the king and queen of the asanas—and they can be rather cavalier with their subjects' necks. Be smart but undaunted: They grant great boons to those who approach with respect.
Yoko Yoshikawa teaches Iyengar-based yoga in Oakland, California.