Yesterday, I did a yoga session with a friend at the Charlottesville Hot Yoga Studio, which is just around the corner from the OESH factory. The 90 minute session was terrific in all aspects, including making me think about the biomechanics of the poses we did. Every day, I do a modified Warrior Pose/Lunge Exercise, as I demonstrate above and describe here along with my scientific rationale.
I’m one of a number of people who’ve studied the biomechanics of various yoga poses with a 3D motion and force plate instrumented laboratory and in 2005, my research team and I published one of the first studies of the effects of yoga on walking here. That work led me to become a peer-review expert on yoga, being called upon, for example, to evaluate research proposals on yoga for federal funding.
Studying the biomechanics of walking and running led me to yoga much like it led me to make shoes. I found in our laboratory several things that had never been noticed before. The specific discovery leading to yoga was an isolated reduction in peak hip extension at the end of stance that consistently occurred in various pathologies and as we age (as I further describe and give references for, here). That finding could very well help explain why many of us get low back pain and have difficulty maintaining balance as we get older.
One of the ways I looked to improve this walking abnormality was yoga. I knew there to be several yoga poses that stretch the hip into extension, including the Sun Salutation and Warrior Poses. I hypothesized that yoga, which typically includes one or more of these stretches, would improve peak hip extension during walking. Indeed, that is what we found. We performed a preliminary study in healthy elderly subjects, which led to studies in other populations.
Of course yoga includes much more than just one or two poses that stretch the hip into extension. But at least we had a biomechanical foundation for understanding some of yoga’s physical effects. Which I believed was important to advancing our understanding of yoga, as well as exercise in general. It took time to get the powers-that-be interested in funding studies on yoga. On one extreme, there were the traditional Western trained physicians and scientists who didn’t understand yoga enough to be able to study it. On the other extreme, there were some outspoken yogis who believed that there was nothing about this ancient and unique mind-body practice that needed proving.
Meanwhile, yoga has exploded in popularity. And more and more people have turned to yoga for exercise and relaxation, as well as relief of bone, joint, and muscle-related pain. And in 2012, William Broad published a book “The Science of Yoga: The Risks and Rewards” that gave pause to many would-be yoga doers as well as put a whole new scrutiny onto yoga teachers. In his book, Broad brought to the public the many health benefits of yoga but also, a number of injuries that have occurred with yoga. While the book caused controversy in the yoga world, I believe much good has come out of it, including an appreciation for biomechanical research which has led to not only safer, but more effective poses.
George Salem, Ph.D. and his research group at the University of Southern California (USC), have been studying the biomechanics of a number of yoga poses in the healthy elderly population, described here. George is a former classmate of mine from UCLA where I received a Masters of Science in Kinesiology. For several years now, George has been studying yoga poses at USC using the same 3-D motion and force plate analysis techniques that I used at Harvard and at UVa. That type of analysis has allowed George and his team to evaluate for any given yoga pose, what muscle groups are stretched and strengthened and which ligaments and joints might be overstretched or over stressed, predisposing to injury.
George and his team have shown that several yoga postures aren’t working on the joints and muscle groups in the way that many yoga teachers had thought they were. They’ve also shown that some poses that were thought to decrease stresses to joints, actually increase stresses to joints. Their research has improved the practice of yoga, helping yoga teachers make modifications to a number poses. Most importantly, their research has led to the general recommendation that routines of poses always be tailored to an individual based on his/her musculoskeletal limitations.
With this research at hand, this is the current advice on yoga given by the American Academy of Orthopedic Surgeons:
“The American Academy of Orthopaedic Surgeons (AAOS) believes the rewards of basic yoga outweigh the potential physical risks, as long as you take caution and perform the exercises in moderation, according to your individual flexibility level. These rewards include improved strength, balance, and flexibility, as well as improved sense of well-being. Yoga may also be beneficial for certain bone and joint problems like carpal tunnel syndrome, tennis elbow, and arthritis.
Be aware that whether yoga enthusiasts are just stretching or assuming specific positions, serious muscle damage and related injuries can result if they do not take the proper precautions, especially for people with pre-existing musculoskeletal ailments or conditions.
According to the U.S. Consumer Product Safety Commission, there were more than 7,369 yoga-related injuries treated in doctors’ offices, clinics, and emergency rooms in 2010. Common yoga injuries include repetitive strain to and overstretching of the neck, shoulders, spine, legs, and knees.
There are many things you can do to help prevent yoga-related injuries.
- If you have any medical conditions or injuries, speak to your doctor before participating in yoga.
- Work with a qualified yoga instructor. Ask about his or her experience and credentials.
- Discuss any known illness or injury with your yoga instructor prior to the class so that he or she can recommend pose modifications.
- Learn what type of yoga you are performing. There are hundreds of different forms of yoga, some more strenuous than others. It is important to learn which type of yoga will best suit your needs.
- Select the class level that is appropriate for you. Beginners should start slowly and learn the basics first — such as breathing — rather than trying to stretch too far.
- Wear appropriate clothing that allows for proper movement.
- Warm up thoroughly before a yoga session — cold muscles, tendons, and ligaments are vulnerable to injury.
- If you are unsure of a pose or movement, ask questions.
- Know your limits. Do not try positions beyond your experience or comfort level.
- Keep hydrated by drinking plenty of fluids, especially if participating in Bikram or “hot” yoga.
- Listen to your body. If you are experiencing pain or exhaustion while participating in yoga, stop or take a break. If pain persists, talk to your doctor.”
My personal experience doing yoga has only reinforced my appreciation for having a good yoga teacher who understands current biomechanics research. The teacher I had yesterday appropriately told us not to do anything we didn’t feel comfortable doing. And when we did a pose called the Pada Hastasana where an experienced yogi can bend down to put his/her hands under their feet, he enforced that it wasn’t necessary to get our hands all the way to the floor but rather it was important to keep our backs straight. Even if that meant for some, getting our hands down only as far as our knees. Doing that pose in this modified way stretches the hamstrings without stretching the small ligaments running along the back of the spine.
I can’t speak for each of the numerous yoga studios and teachers who may or may not be in-tune with current biomechanics research. But yesterday, leaving the Charlottesville Hot Yoga Studio, I felt better. More relaxed, happier. In a way that was different than after I go for a run. And all day today, I’ve been thinking much more about my posture and my movement, which is always good!
