The so-called King of all asanas aka salamba sirsasana aka supported headstand is one of the crowning achievements in yogasana. If you can perform headstand, you join an elite group of yogis. If you teach it, especially to a group of wide-eyed beginners, you are a yoga rock Goddess. Another teacher once bragged to me that, within some period of time (months? a year? I can’t recall), every student in her class was able to perform sirsasana. I taught it at one time too. Before I had any business teaching it. I continued to teach it after I considered myself qualified. What qualified me? The usual stuff – I regularly practiced it. I read and watched tutorials on the internet and in books. I learned from other teachers. I took a couple of workshops.  I taught headstand because I craved the status. I desired to impress. I delighted in being responsible and lauded for another person’s accomplishment. I never wanted to hurt anyone. I’d like to say that I didn’t hurt anyone. But I don’t know. There were no reports of injuries. But, then again, I’ve had students confide in me about injuries sustained in another yoga class, including one suffered from prep work and attempts at headstand, but these students never told the other teachers.

But here’s the thing. I thought that if I followed the cumulative wisdom of alignment in headstand that I, and anyone I taught, would be safe from injury. I thought that if I drilled the shoulder girdle prep work into my students ad nasueam (lift your shoulders! lift your shoulders! lift your shoulders!) and dampened my enthusiasm and that of my students by  patience, restraint, and slow, methodical prep work, it would be all good. I was wrong. I liken this King of all yoga poses to King Henry VIII, known for many things, but most notoriously for lopping off tens of thousands of heads during his reign. Nobody knows how many heads have been lopped off by King Sirsasana, because nobody is counting. OK, nobody has literally lost her head with this pose, but we do know that adverse events can and do occur with headstand and that they can be of a serious, life altering nature.

Here is what’s been written up  over the years in case reports in the medical literature and captured in a 2013 review article entitled Adverse Events Associated with Yoga: A Systematic Review of Published Case Reports and Case Series. Keep in mind that this is not an inventory or accounting of the actual number of adverse events caused by yoga. These are the very few cases, where someone experienced an injury or other adverse event directly attributable to yoga; and where that person was seen by a physician, who subsequently wrote about the event and published the case in a scientific journal. What is missing from the number of cases reviewed (76) are the potentially millions of injuries/adverse events that occur each year in the US alone, where over 15 million people practice yoga and pranayama regularly. There is currently no way of knowing how many of these events occur each year because studies large enough to provide a valid estimation have not been done. In the above review of cases, headstand was culprit in 10 of the 76 cases.

Adverse events attributable to headstand included:

• Worsening of vision secondary to glaucoma; this 46 yo female yogi fully recovered in several months by avoiding sirsasana
• Progressive pigmentary purpura – a rusty brown skin patch caused by leaky capillaries (tiny blood vessels) of the forehead; the treatment was topical corticosteroids and the clinical outcome for this 59 yo male was unclear
• Bilateral orbital varices (bulging veins in the eyes) due to increased blood flow;  treatment and clinical outcome were unclear for this 62 yo female
• Basilar artery occlusion aka a stroke; the 34 yo female yogi received inpatient treatment and physical therapy  and had not fully recovered one year later
• Progressive optic neuropathy (nerve damage to the eye) secondary to glaucoma; the course of treatment and clinical outcome for this 46 yo female were unclear
• Bilateral conjunctival varix thromboses or enlarged veins with blood clots in the eyes; the 60 yo male yogi had a surgical excision of the blood clots but the clinical outcome was unclear
• Progressive optic neuropathy (nerve damage in the eye) secondary to congenital glaucoma; the treatment and clinical outcome for this 47 yo female yogi was unclear
• Early glaucomatous optic disk change and visual field loss aka pathological changes in the eye accompanied by worsening vision; treatment for this 29 yo male yogi was avoiding inversions, which stabilized his eye status
• central retinal vein occlusion aka eye stroke; this 55 yo male yogi underwent eye surgery, but did not recover

If I had glaucoma or a family history of glaucoma and a yoga teacher cued headstand without detailing why it would be contraindicated for someone with glaucoma, I would walk run, possibly screaming, from the room because at the very least,  teachers should know this universally agreed upon contraindication. I cringe to say it, but I’ve been in many yoga classes, where headstand was cued, but few of them came with warnings about headstand’s potential effects on glaucoma, detached retina’s, neck issues, or uncontrolled blood pressure. And then, confounding matters and tarnishing the shine I feel when I call my teaching style “Iyengar-influenced,” there is this, from B.K.S. Iyengar from his seminal work, Light on Yoga: “I have taught this pose to a lady of 65 who was suffering from glaucoma. Now she finds the eyes are completely rested and the pain in them is much lessened. Medical examination revealed that the tension in the eyeballs had decreased. I am mentioning this to prove the value of the correct head stand.” One could not be faulted in believing that a good teacher can align the bad away in sirsasana, even though numerous case studies, as well as full research studies, show that intraocular pressure rises in headstand and exacerbates glaucoma.

While I have a macabre fascination with headstand-induced strokes and vision loss, my real interest lies in the biomechanics of sirsasana and potential or actual musculoskeletal injuries to the cervical spine.The weight of an average adult head is 7.5% of total body mass. Your cervical spine was designed to carry the weight of your head, or about 7.5% of your total weight. In headstand, as you will learn later, you ask your neck to bear upwards of 50% of your body’s mass. For example, I weigh 125 lbs, so my head weighs about 9 lbs. Thus, my neck has a loading history of hauling around 9 lbs give or take a hat. However, when I perform headstand, I potentially place more than 60 lbs of weight onto my cervical spine, which, again, has a loading history and capacity of 9 lbs or less. Vertebra are made of trabecular bone, which is the spongy variety and more prone to fracture. Loading beyond tolerance levels subjects your neck to the possibility of a burst fracture. Burst, in case you need reminding of its definition means “to break suddenly and violently apart, spilling the contents, typically as a result of an impact or internal pressure.” Not something you want associated with your neck. But a more likely scenario, detailed below, is the possibility of spinal cord compression by a compromised cervical spine.

What I found remarkable about these cases was that none is the type of musculoskeletal injury you might expect to find when you  hold the majority of your body weight on the fragile vertebrae of your neck. To an emergency room physician or orthopedic doctor seeing a headstand-related neck injury, it’s going to be a no-brainer. A neck injury, where you might expect one, is neither as fascinating nor case-worthy as, say, a pneumothorax (collapsed lung) caused by Kapalabhati or breath of fire. So, I went searching and found a few case studies that were not included in the 2013 review article. In one case, a 63 yo woman, who had practiced yoga for 30 years and had a daily headstand practice, presented with bilateral hand numbness. Imaging showed severe multilevel degenerative disc disease, spinal stenosis (narrowing of the spinal canal in which the spinal cord runs), and secondary compressive myelopathy with myelomalacia  aka compression of the spinal cord by the vertebrae. In another case, a 63 yo man presented with history of tingling & numbness in his finger and toes, weakness and stiffness in all four limbs, and frequency and urgency of urination. There was no history of trauma to his neck or back. For 25 years prior, he had done headstand daily. He, too, was found to have cervical compression of his spinal cord. While case studies are captivating, they don’t tell us that much. What I needed was a research study. What I found, was even better. I uncovered a Master’s Thesis completed in May 2012 by Rachel E. Hector from the University of Texas, Austin, entitled Sirsasana (Headstand) Technique Alters Head/Neck Loading: Considerations for Safety. I could not have dreamed of a better find.

Here is how the study played out. Three groups of 15 yogis practiced one of three variations of sirsasana. Variations occurred in the entry and exit  from the postures, while the actual holding of the headstand was the same for each group. Group 1 entered and exited sirsasana by lifting/kicking one leg up at a time; Group two bent both knees, then straightened them together; Group 3 extended both legs and lifted symmetrically, in a pike position. I present a sketch of the entry techniques from Hector’s thesis.

Three ways to enter/exit headstand

Participants performed their respective variations, holding for 5 breaths, while a force plate beneath them measured peak forces acting on the head and neck, loading rate of those forces, center of pressure, and neck angle in the frontal plane at C3 (cervical vertebra 3). The study study examined the weight-bearing responsibility of the head and neck – separate from the arms, which I found to be a critical parameter. You can read Hector’s thesis to learn how they rigged the force plate to eliminate interference by arm forces.

Highlights of the study revealed:

• the average yogi loads the head with 30-50% of his or her body weight while performing headstand
• Individuals entering the posture with legs extended and together (pike position) exhibited the lowest maximum and average forces during entry with over 75% of participants using this technique staying below the threshold of vertical loading known to cause cervical failure (image on far right)
• Individuals entering the posture by lifting/kicking one leg at a time experienced the greatest forces on the neck, with more than one half of them experiencing forces above the loading threshold for potential cervical failure (image on far left)

If headstand is responsible for an unknown number of strokes, vision loss, and debilitating damage to the cervical spine, why is still practiced and taught in most yoga studios? I think the reasons can be complex and beyond my ability to articulate nuances of empowerment, sacrifice, injury, and redemption in yoga. The courageous, thoughtful, and frankly brilliant Matthew Remski, the most compelling writer on philosophical aspects of yoga injuries, explores these ideas in his heady WAWADIA Project . I can not recommend it enough. I’ll go further, you should pre-order a copy of his soon-to-be-published-but-not-soon-enough book (which was crowd-funded, no less), because it’s first printing will sell out.

While Matthew wades through the deep stuff, I’ll pluck the low hanging fruit and merely bullet a list of popular, but mostly unexamined, “medical” benefits of King Sirsasana, tidily summed up in this giddy, optimistic article 10 Awesome Medical Benefits of Headstand. Fortunately, there are practitioners out there like Dr. Kathleen Summers, another yogi doc, who writes in a fairly balanced three-part post about the purported benefits of sirsasana and some potential dangers,  addressing several of these claims.While some of them are reasonable and may be valid, most are unexamined. My comments are in brackets.

The 10 [so called] Medical Benefits of Headstand

1. Relieves stress [possibly for some; for others, it will likely increase stress hormone secretion]
2. Increases focus [definitely]
3. Increases blood flow to the eyes [yeah, that thing about glaucoma]
4. Increases blood flow to the head & scalp [uh, no; the body has a highly regulated, secure system that will not throw the brain under bus for folly or whim]
5. Strengthens shoulders and arms [yes and yes; in fact, Dr. Loren Fishman, a world-renowned rehabilitation physician and long time yoga practitioner and teacher, in a small pilot study (10 participants), produced remarkable results using sirsasana and even sirsasana prep work to heal torn rotator cuffs.]
6. Improves digestion [huh? what? digestion is a downward action; human physiology is designed to push food, urine, feces, menstrual blood, and babies down and out; this makes about as much sense as having a delivering mother stand on her head to improve the birthing process. Ugh.]
7. Helps flush out the adrenal glands [really? please elaborate]
8. Decreases fluid build up in the legs, ankles & feet [yes, it will increase venous blood return, but only while you are in the pose]
9. Develops strength in the core muscles [yes; this is more likely with a controlled pike variation of entry and exit; but while stabilized in headstand, the same alignment applies as in Tadasana – neutral pelvis and ribs to bring the core musculature to its appropriate length for maximum force generation]
10. Stimulates the lymphatic system [yes, but a better, safer way to stimulate your entire lymphatic system is whole body movement such as walking in alignment.]

When these master-blessed messages are perpetuated in books, magazines, videos, websites, and by a staggering number of teachers in countless studios, then you have potentially hundreds of thousands of people clamoring to honor the King, without a clue that sirsasana can be a very nasty ruler indeed. While it is possible to suffer a musculoskeletal injury in just about any yoga pose, the stakes for musculoskeletal AND other adverse events like stroke and vision loss are higher than most would be willing to wager – if only they knew.

So, I end by circling back around to the work of Rachel Hector (who, by the way, recently published her findings in the Journal of Bodywork and Movement Therapies) and leave you with my recommendations, based on her work, for practicing sirsasana – IF you still feel compelled to practice it. But first, let me be very clear about some contraindications and caveats.

Contraindications:

• If you have glaucoma or uncontrolled blood pressure, do not practice sirsasana
• If you have low bone density in your spine, do not practice sirsasana
• If you have degenerative discs in your spine, do not practice sirsasana
• If you suspect that sirsasana is injuring you, do not practice sirsasana
• If you feel pressured by teachers, students, media, or your own ego to practice sirsasana, do not practice sirsasana
• If you are 35 of older (the age range with the highest risk for disc degeneration), do not practice sirsasana, and if you do, do not practice it daily. While Hector’s study did not find age to be a factor (her study subjects ranged in age from 18-60), intervertebral immobility and disc degeneration come with aging. Large, repeated, asymmetrical loading onto immobile, degenerative cervical discs that are not designed to withstand 50% of your body weight can, as the cases studies highlighted earlier, cause cervical failure resulting in neurological damage to the spinal cord. This damage is cumulative. You may not know its happening until one day, you know it’s happened.

Caveats:

• According to Hector’s study, the taller you are and the more you weigh, greater are the loading forces and loading rate applied to your neck
• Men tend to have higher loading rates and maximum forces on the cervical vertebrae (largely explained by their greater weight), however, studies on male cadavers have consistently shown that males have a much greater loading capacity before cervical failure occurs. Are you one of the lucky ones?
• The subjects in Hector’s study ranged in yoga and headstanding experience from 6 months to 20 years and that experience was not a predictor of any outcomes. It bears repeating: headstanding experience was not a predictor of any outcomes. Experienced headstanders, with as much as 20 years experience, had no added protection from negative cervical spine outcomes. This was the most surprising result of the study and possibly the most important to the yoga community. There is a perception that if you get hurt in yoga, it is your fault, that you were novice, or not practicing good alignment, or you weren’t ready for the asana you were attempting. Matthew Remski, once again, illuminates these perceptions brilliantly in a piece on headstand that inspired me to begin consideration of its risks. The darker side of this coin is that if you are experienced and in good alignment, you might think you won’t get hurt. But in reality, being experienced at headstand may not protect you and being inexperienced may not put you at greater risk for injury. I can’t quite wrap my headstand head around this, but it bears consideration.

Recommendations for practicing Sirsasana:

• Enter with legs extended (no bend in knees) and lift, symmetrically, in a controlled manner. This method of entry measured the least amount of forces to the neck and occurrences of sudden changes in loading, as it loads the head and neck slower than the other methods. This method of entry requires more intense upper body activation and controlled loading – essentially a better strength to weight ratio that kicking one leg up at a time.

B.K.S. Iyengar entering sirsasana

• Exit the pose quickly, by allowing one leg to drop to the mat in a controlled manner. This method of exit, as opposed to the pike exit, appears to reduce over-flexion of the cervical spine upon exit. Flexion-compression, also called pre-flexion or axial loading, loads the cervical spine without is natural curve and is the most vulnerable configuration of spinal alignment, which can result in spinal injury due to buckling failure.

The king is dead. Long live the king.

Namaste, Michele