Dr. Sinaki promotes weight-bearing movements of the body. Working against gravity induces bones to thicken and become stronger. She also emphasizes exercises that extend the back (back bends) to build bone strength in the spine. These exercises are most helpful for those who suffer from osteoporosis, a disorder of gradually thinning bones that leads to an increased risk of painful fractures.
Recently, Dr. Sinaki published a concerning report about Yoga. She described three people who were healthy except for some mild thinning of the bones in the spine, a condition called osteopenia. It’s a precursor to osteoporosis that is a more mild loss of bone density.
The three people in her report had started a Yoga practice to improve their condition. Instead, they got worse. Rather than build bone strength and reduce their risk of fractures, they developed new compression fractures which caused neck and back pain. Compression fractures are collapsed vertebrae, the bones of the spine.
Strenuous spinal flexion exercises were determined to be the cause of the new compression fractures. Pushing to bend too far forward in pascimottonasana or padahastasana, for example, can place too much stress on the vertebrae. The added stress contributes to their collapse.
Dr. Sinaki’s latest publication backs up data she originally reported in 1984. She had found that increased torque pressure from forward bending can worsen osteoporotic disease rather than fix it.
Her previous publication focused on those diagnosed with osteoporosis. The latest one extends the concern to those with osteopenia, weakened bones that aren’t yet brittle enough to be called osteoporosis.
In the 1984 research, 50 women with osteoporosis of the spine were randomized to protocols of spinal extension (back bends), spinal flexion (forward bends), combined extension and flexion, or no therapeutic exercise. After one to six years, x-rays were repeated and compared to pre-treatment films. New fractures occurred in all groups.
In the control group, two out of three (67%) of the patients developed new wedging or compression fractures. This indicates that the natural history of the disease is for it to worsen. If you do nothing to correct the problem, the bones will continue to deteriorate.
Exercise helps, particularly backward bends that are common in Yoga practice such as bhujangasana (cobra) and shalabhasana (locust). In the extension exercise treatment group, only 16% of the women developed worsening disease, a big improvement over the “do nothing” group. Back extension exercises are protective against worsening osteoporosis of the spine and new compression fractures.
But in the group practicing only flexion exercises of the back (forward bends), almost nine out of 10 of the women (89%) were worse off than the control group. They had MORE compression fractures than the people doing nothing to try to improve their condition. They were worse off for their effort.
The combined treatment group, those practicing both flexion and extension back exercises, didn’t fare much different from controls. They potentially had a small improvement as 53% developed new wedging or compression on their spinal x-rays compared to 67% of the “do nothing” group, but the result wasn’t statistically significant. Essentially, the protective effects of back extension exercises were counteracted by the damaging effects of forward bends so that overall there was no improvement or detriment by practicing forward bending and backward bending exercises during the study period.
It’s limited research, but there is cause for caution when it comes to forward bending asanas for anyone with osteoporosis or osteopenia.
Since many people are unaware they have thinning bones, it’s wise for us all to be careful. A new fracture is how many people learn that their bones have become brittle. It’s important to practice with awareness and to be mindful of proper technique at all times.
The way pascimottonasana and other forward bends are performed is important. Severe rounding of the back is the likely culprit when it comes to the potential detrimental effects of forward bending asanas. Bend from the hips and keep the back fairly straight. Don’t worry if the head doesn’t reach the knees. It may make the difference between a healthier back and a damaged one. (Unfortunately, Dr. Sinaki’s papers didn’t look at technique.)
Bottom line: An increasing number of middle-aged and older Americans are practicing Yoga, and many have thinning bones. Yoga is great for them as a properly designed practice can strengthen the skeleton, decrease the risk of falls by improving balance, and improve posture and rounding of the back. But caution is indicated when practicing forward bends like pascimottonasana and padahastasana. For those with osteoporosis or osteopenia, it may be best avoid them altogether. For all other practitioners, it’s important to practice proper technique. Bend from the hips and keep the back straight without rounding.
Kathleen Summers, MD, PhD, is a contributor to Prevent Yoga Injury. She is a board-certified internist specializing in natural, Yoga-based care. Dr. Summers is a graduate of Northwestern University Medical School in Chicago and holds a second doctorate in neuro-pharmacology from Southern Illinois University. Currently, she is an Adjunct Clinical Instructor at Southern Illinois University School of Medicine, and she is a member of the American College of Physicians, the American Society of Nutrition, and the International Association of Yoga Therapists.
During her frequent travels to India, Dr. Summers researches Yoga and its therapies. She enjoys uniting her two passions, Yoga and medicine, and is continually exploring Yoga's healing concepts and integrating them with modern, evidence-based care. Her primary Yoga influences have been the tantric styles of Sivananda and Agama. She holds a 500-hr Yoga teacher training certification. You can also follow Dr. Summers on Facebook and Twitter.