Twisting postures are an enjoyable, challenging, and some might say vital part of our yoga practice. Poses like marichyansa/Marichis pose, revolved poses like parvritta trikonasana/revoloved triangle ,and parvritta parsvokonasana/revolved extended side angle pose allow us to move and lengthen our spines to improve our spinal and pelvic flexibility, as well as our strength. Traditionally twists are thought to be detoxifying, literally wringing out the organs of digestion and detoxification. To better understand the benefits and considerations surrounding twists, let's take a closer look at the spine.
The spinal column is formed by 24 mobile vertebrae, and the nine fused and immobile remnant vertebrae of the sacrum and coccyx. Each mobile vertebra is separated by a shock absorbing, jelly filled disc. The vertebrae move and glide in relation to each other according to the angle of the joints between each vertebra, known as facet joints. There are four facet joints per vertebrae – two joints on the left and right part of the top of the vertebrae, and two joints on the left and right part of the bottom of the vertebrae. The angle of the joints dictates how much motion can occur in each part of the spine.
The spine is divided into the seven cervical vertebrae of the neck, the twelve thoracic vertebrae of the mid back, and the five lumbar vertebrae of the low back. The neck is the most mobile section of the spine with generous movement in flexion, extension, and rotation. The angle of the facet joints change as we move into the thoracic spine where flexion and extension are limited (also due to the attachment of the rib cage) and rotation is free. In the lumbar spine the angle of the joints change once again, flexion and extension is freely available but rotation is limited. These restrictions in movement are literally created by bone meeting bone and preventing further motion. Of course there is muscle and connective tissue that covers the vertebrae, and if certain muscles are tight or shortened, this can further prevent motion in certain ranges.
In twists, we can create more space by preserving the height of the discs between each vertebra. When we slouch, or the discs begin to degenerate, the disc ‘squishes' and looses its height. This further restricts our motion by allowing the ‘bone on bone' effect to occur sooner. This is particularly relevant in the lumbar spine, which is already limited in its rotational range. When entering a twist, inhale and lengthen from the tail to the head, imagining your healthy, pink discs springing back to their fullest height. Once you've created the room, exhale and twist, recognizing that the majority of your motion will be occurring firstly in your neck and second your mid back. With every inhale create a little more space, and with every exhale softly move into the space as you twist a little further.
Special Considerations for Standing Twists
In standing twists, such as the revolved poses, we often add an element of flexion at the waist. When we are moving purely from our hips joints, and maintaining the natural front to back curve in our lower spine, twists are a healthy and satisfying pose. Problems begin to develop if we start to also flex or round in our lower spine. This might be due to tightness in our low back, our hips, or a compensation for stiffness further up the spine – and this predisposes us to injury.
The most likely position for your disc to herniate - or bulge out pressing on a nerve - is in flexion combined with rotation. As the spine flexes forward, the disc moves backward, and as we move backwards, the disc moves forward. So when we put the disc in a position where it is moved to the back of the vertebrae, then increase the pressure by adding rotation – we leave it vulnerable to injury.
If you know you are at risk for a disc herniation – such as suffering a previous injury to your discs – stick to seated twists, or significantly decrease the amount you twist in your lumbar spine and focus on your thoracic spine. All of us can be mindful of sticking to flexing at our waists, and avoiding rounding into our lower spine.
Special Considerations for Seated Twists
Depending on the flexibility of our hamstrings and lumbar spine, when we come to the floor we may find our pelvis tipping backwards, resulting in flexion into our lumbar spines. An easy way to check this is to find the top of your pelvis - your iliac crests - with your hands. Sitting with knees bent, feet flat on the floor, place your hands at your waist and press in slightly, so that your thumbs are towards your back, your fingers wrapping towards your front, with the space between your thumb and first finger is fitting into your waist.
Move your hands down until they come to rest on a ridge – this is your iliac crest. Play with tilting your pelvis back and forth by tucking and sticking out your tail, and notice how your hands move. When you tuck your tail under, your fingers start to point upwards, stick out your tail and your fingers point downwards. The pelvis is in neutral if the hands are making an arc on the crest, fingers arcing down at the front, and thumb arcing down at the back.
In addition you can observe how the lumbar spine adapts with these motions – rounding and removing the lumbar curve with a tuck of the tail, and increasing the low back curve as we stick out the tail. Now extend your legs out and notice what happens to your pelvis. If it starts to tip backwards (fingers up) then you would benefit from taking some height under your sitting bones by sitting on the edge of a folded blanket or foam block. Take enough height that your pelvis moves towards neutral. Just as in standing twists, in seated twists we want to eliminate the addition of flexion into the lumbar spine so as to protect our discs and receive the full benefit of twists. Enjoy the curves.
Twists can take us deeper into our practice by lengthening and strengthening our spines in ways that allow us to venture further into other poses. When we become aware of our antomy we can practice safely and with confidence to receive all the benefits that twist hold.
Read other articles by Dr. Robin Armstrong:
Asana Anatomy-Downward Facing Dog
Dr. Robin Armstrong has combined her decade of experience as both a Chiropractor & Yoga Instructor to develop a unique type of yoga therapy known as Yoga Rehab, blending traditional yoga practices with modern rehab exercise to help students overcome pain and injury. She has shared her knowledge of yoga injury prevention and anatomy with the Canadian Press, American Council of Exercise, Impact, and Alive magazines as well as many local yoga teacher training programs. She practices at YYoga Downtown Flow studio in Vancouver, Canada.
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