Have you ever polled your students to discover why they come to class? After all, they allocate the money and the time—perhaps the more precious commodity—to attend your classes. Some are coming for health benefits or fitness, some for improved flexibility, and some may even come for social connections. But I suspect you'll find that a significant number come to class for a respite from their high-stress lives, to experience relaxation and learn how to release tension from their muscles.
As their teacher, how do you incorporate relaxation, besides Savasana (Corpse Pose), into every class? Many studies, including biofeedback and other disciplines, have shown that relaxation of the muscles in the neck, jaws, and face can have powerful calming effects on the entire nervous system. Even gentle reminders to relax the jaws during asana practice can help. And there are many yoga poses that stretch the neck, inviting the neck muscles to let go and lengthen. However, not all neck positions are safe for all students, and a good teacher will exercise some caution when working with students' necks.
What Could Go Wrong?
There are two concerns to keep in mind when working with neck positioning in yoga. One is the blood circulation that moves from the heart to the brain via the neck, and the other is the structure of small facet joints and nerve pathways on the back of the neck. Impeding either the circulation to the brain or the nerve pathways from the neck can cause serious problems—lack of oxygen to the brain; and numbness, weakness, and pain down the arm caused by a compressed or "pinched" nerve in the neck. How do you help your students avoid these costly, potentially devastating injuries?
To understand the fundamentals of neck positioning in yoga, let's take a look at the structure of the cervical spine. The bodies of the vertebra are separated by the discs, and where each two vertebra overlap, there is a small facet joint on each side at the back. An arch of bone (the neural arch) projects from the back of each vertebral body. It surrounds and protects the spinal cord, and the nerves leave the spinal cord through the intervertebral foramen (holes between each two vertebrae) at the back edge of each disc. Problems arise when the cervical spine starts to develop "normal" degenerative changes—as early as the mid-thirties among today's Westerners—and the discs narrow and dry out, the little facet joints develop wear-and-tear arthritis, and the intervertebral foramen become smaller.
With these degenerative changes, in certain neck positions, the foramen (where the nerves exit the spine) become even smaller and can compress or pinch the nerve, causing pain, numbness, and weakness wherever that nerve travels to in the arm. These symptoms can be mild and temporary or severe and persistent, requiring medical treatment. And what are the risky neck positions? Neck hyperextension (hanging your head back, which opens the throat but compresses the back of the neck), especially if it's combined with pressure on the top of the head in poses such as Matsyasana (Fish Pose). Another is hyperextension combined with twisting or rotating the neck, as in neck rolls. These positions also compress the little facet joints on the back of the cervical vertebra, which can cause further damage to already degenerated cartilage surfaces.
Neck hyperextension can also impede the blood circulation to the brain. The brain receives blood from arteries in the front of the neck (the left and right carotids) and the back of the neck (the vertebral arteries). The vertebral arteries wind their way up through the back part of the cervical vertebrae and pool their blood with the carotids in the Circle of Willis, which distributes the blood throughout the brain. If the carotids are significantly blocked with arterial plaque—not uncommon in our society—and you hyperextend your neck, putting pressure on the vertebral arteries, blood circulation to the brain will be reduced. This can cause dizziness or even a temporary loss of consciousness, which can lead to a fall, with possible injuries from the impact.
What to Do about It
So what are the implications for yoga teachers? Unless you're teaching a class of teenagers and twenty-somethings, neck rolls are forbidden. Don't invite your students to hang their heads back in Virabhadrasana I (Warrior Pose I), Urdhva Mukha Svanasana (Upward-Facing Dog), or Ustrasana (Camel Pose) unless they have enough chest, shoulder, and upper-back flexibility to extend their necks without compression in the back of the neck. In other words, if the chest is dropped and you look up to the ceiling, the back of the skull presses down into the back of the neck. If you can lift your chest in these poses so the breastbone is nearly parallel to the ceiling, your head can hang back without compression. Try it yourself.
While teaching, challenge yourself to find new ways to invite neck relaxation without involving neck rolls or hyperextension. How about just hanging the head to one side, ear toward shoulder (keep shoulders level)? Then breathe and relax into the side neck stretch. Or simply drop the chin toward the chest (keep chest lifting up toward chin), and hold and relax into the back-of-neck stretch, which is also a great preparation for Sarvangasana (Shoulder Stand). With a little creative thinking, you can help your students experience neck muscle relaxation in safe and comfortable positions.
Julie Gudmestad is a certified Iyengar Yoga teacher and licensed physical therapist.