I was recently at the yoga conference in Vancouver and attended a course on low back therapeutics. The instructor, Martin Kirk, an inspiring passionate yogi, with a biomechanics background, addressed one of the most common ailments of Western society – low back pain, and specifically stress to the lumbar discs, leading to disc bulges and herniations. Given the short two hour time span of the course and North America’s propensity towards sitting for extended periods of time, I felt this was a fair place to start when teaching low back therapeutics and yoga. Of course having spent a few years working in a therapeutic setting addressing low back injuries, I am well familiar with the spectrum of low back disorders and the awareness that “one size does not fit all” when it comes to rehabilitating the low back… which is why this blog post will be part one of a series of low back health and yoga. *For simplicity we will focus on the low back in this discussion; however, disc problems can be found often in the cervical spine, and sometimes in the thoracic spine – not to be ignored, but addressed in a future blog post.
Disc problems are so common in our western society largely because we spend so much time sitting – computers, television, driving, starbucks, etc. Looking at the anatomy of the spine, there are four main curves that the vertebrae and discs follow: the cervical (the neck) curving inwards (towards the front of the body), the thoracic (mid back) curving backwards, the lumbar (low back) curing inwards, and the sacrum curving backwards. When most of us sit, we round and slump our backs which flattens out the curve of the lumbar spine, and leads to a cascade of “misalignments” the whole spine up as the body tries to right itself like a boat.
So why is lumbar flattening a concern? The discs, our shock absorbers, are like little tires between each vertebra. They have an outer, thick ring of ligamentous tissue and on the inside a soft, jelly-like material to give it the “spring” when compressive forces are placed on it. When the lumbar spine is taken out of its neutral inward curving alignment and reversed, it places a backwards pressure onto the discs, in essence bulging the disc structures backwards. This is not to say it is dangerous to move the disc in this way, it is more an application of too much of one thing isn’t good. In other words, it is good to know the spine can withstand forward, backwards, and side to side pressure, but constantly always moving in only one direction over extended periods of time can lead to structural changes in the discs from the unequalized pressure.
Constant or forceful backwards pressure on the discs can eventually result in tearing of the disc’s outer rings, allowing the gel in the center to push out. This is known as a disc herniation, which is functionally equivalent to a blown tire. And because the spinal cord and its nerve are posterior to the discs, a nasty side effect of the bulge pressing backwards or slightly off to the side is pressure on a nerve root, potentially causing nerve impairment and pain.
Additionally, the lumbar spine’s alignment is strongly affected by the pelvis and the lowest portion of the spine, the sacrum’s positioning. It is helpful to look and the pelvis as the base from which the rest of the spine will follow. If the pelvis and sacrum (which are secured together by strong ligaments) are positioned in one direction, the lumbar spine is also pulled in that direction. And a common “misalignment” of the pelvis/sacrum is a posterior rotation (tail bone tipped downwards), which often correlates with tight hamstring muscles. In this scenario, beware the forward bend (here’s where we return to yoga). When a person with tight hamstrings bends forward, the tendons of the upper hamstrings pull at the base of the pelvis, tipping it into a posterior rotation, leaving the lumbar spine to flex deeply (reversal of its natural curve) and perform the bulk of the bend.
What we hope to teach our students is that ideal back alignment follows the natural curves of our spine (not straight), which will even-out the pressure on all sides of the disc. In a forward bend, we can promote neutral spine positioning by making sure the pelvis tips forward with the bend. For the person with tight hamstrings this can be promoted by bending the knees slightly, widening the feet and learning to activate an anterior tilt of the pelvis. This is good information for general prevention of disc injury and especially for safety of those students already dealing with flattened lumbar spines or who have disc damage.
Regardless of whether the forward bend is seated, standing, or somewhere in between such as down dog there are ways to promote neutral spinal alignment in yoga either with body alignment cues or use of props. Below are a series of pictures representing common alignment tendencies in forward bends and ways to correct or promote better spinal alignment for the student with lumbar disc concerns.
First looking at Uttanasana (standing forward bend). The picture on the left demonstrates the appearance of a student bending primarily through the spine (rounding of the back); again, likely correlating with tight hamstrings. The picture on the right demonstrates how a slight bend through the knees can relieve the pull of the tight hamstrings, freeing the pelvis to move with the spine and reducing the curvature through the back. Cueing your students to tilt the tail bone or lift the sit bones towards the ceiling helps promote the forward tilt of the pelvis. Also, a nice wide separation between the feet and cueing the student to inwardly rotate the top of the upper thighs can free the space for the pelvis to tilt in this fashion.
Next we have two pictures of Adho Mukha Svanasana (down dog). In the picture on the left notice the rounded back appearance. If you see this posture on a student, encourage them to move the hands further away from the feet and suggest wider space between the feet. If back health is your goal in this pose, tell your students it’s okay to bend the knees slightly, as in the picture on the right, and work towards a straight leg/heel on the floor positioning down the road. These suggestions will allow space for anterior rotation of the pelvis (sit bones towards the ceiling) and will provide your student greater ease to lengthen through the spine and minimize the rounding associated with posterior disc pressure.
Lastly, we look at Paschimottanasa (seated forward bend). Again, in order to promote more neutral spinal alignment, have your student sit on a small cushion or block and bend the knees slightly to remove the posterior pull of tight hamstring muscles. Also teach slightly wider leg positioning, lengthening through the spine, shifting the sit bones back, and leaning forward from the hips only as far as they feel a stretch into the posterior leg muscles.
If some of these postural suggestions seem mechanical and rigid to you, it is true. Of course in yoga it feels wonderful to sometime just relax and surrender into a pose as the body naturally folds. However, these tips are meant for education of low back health and to help you understand the why’s of certain postural alignment suggestions. So use these tips as just part of your tool set in practicing or teaching yoga.
In part II of this post we will look at how promoting flexion or rounding of the lumbar spine can actually be relieving and healthful for other students since one size does not fit all when it comes to postural alignment and back health.