Dangers of Lumbar Flexion in Yoga
Consider the number of times you flex forward at the waist or hips in a yoga class. Lower back flexion in yoga presents a number of risks when done improperly. We often hear our yoga teacher telling us to hinge at the hips instead of the lower back. Let’s consider what these cues really mean and offer in creating a safe forward bending yoga posture. First of all we have to go through a bit of yoga anatomy and biomechanics to understand the issues involved in this common movement.
Our spine is composed of twenty-four mobile vertebrae. The cervical spine includes the top seven vertebrae, while the thoracic spine is made up of the middle twelve, and the lumbar spine completes the count with the bottom five. Below the last lumbar vertebrae are the sacrum and coccyx. The sacrum is a triangular shaped bone that is actually the fused remnant of five sacral segments. The coccyx, also known as our “tailbone,” is an even smaller triangular bone that sits below the sacrum.
Both our cervical and lumbar spines take on a curve that is known as a lordosis. This lordosis essentially means that the cervical and lumbar curves’ concave sides face the front of the body; while our thoracic curve’s concave side faces the back of our body.
In-between each vertebra is an intervertebral disc. The basic functions of the discs are to act as vertebral shock absorbers and as spacers for the spinal nerves to exit the bony vertebral column. Our spinal cord runs down the inside of our vertebrae; each spinal nerve that divides from the spinal cord supplies a particular part of the body with neurological function. This explains many of the symptoms people get when they herniate or bulge a disc (burning, aching, pins and needles, tingling, pain, and weakness through particular parts of the limbs).
Intervertebral discs are round in shape with thick outer borders and jelly-like contents within the border. Each time we bend forward at the low back, the back side (posterior side) of the disc weakens. Over time, with excessive lumbar spinal loading or flexion, the disc develops microtears. Sometimes, these microtears can produce symptoms that are relatively mild; however, when the tears become more significant, symptoms become quite severe. If the thick border has enough microtears or one large tear, the inner jelly-like substance can squish out of the tear to either chemically irritate or physically compress the spinal nerves that exit the spine off of the spinal cord.
How is this complicated anatomy relevant to yoga, picking up a piece of paper off the ground, or even bending over to brush your teeth? Lumbar flexion is the movement of bending forward at the low back while rounding the spine. Due to the lordosis (lumbar curve), this position of flexion increases the likelihood of intervertebral disc microtears which then increases the chances of disc irritation, bulging, and most severely, herniation. A disc injury is one you most definitely want to avoid as they are hard to recover from and they increase your chances of low back injury recurrence; never mind the fact that they cause a lot of pain and can cause symptoms severe enough to require surgery due to neurological complications.
You must now be wondering how to keep your back safe while bending forward either on your mat or in your activities of daily living. When you bend forward, think about keeping your buttocks out and maintaining the natural curve in your lumbar spine. When you are standing straight up and when you bend forward, your lumbar curve should not change shape (much). Hinge forward at your hip joints instead of at your lumbar spine. People always say, “I bend my knees when I flex forward so I am ok!” My answer to that is that you can flex your knees all you want, but if you flex your lumbar spine as well, your back is at risk of injury. If you have to pick something up off the ground, the best way to do it is to both flex your knees AND keep you buttocks out to maintain your lumbar curve.
These principles apply to yoga as we bend forward quite a bit while on our mats. The repetitive action of improper forward flexion is dangerous, so be aware of your lordosis while you flex forward in poses while on your feet, on your back, or on your buttocks. This is even something you should think about while sitting at work; if you slouch through your lumbar spine, you are loading the discs which in time leads to microtears.
Understand your lumbar lordosis as it is your power position in everything you do. Take care of your back by being aware of how you flex forward and never compromise your back to reach further on your yoga mat.
About the Author
What Really Happens in Hip Openers
One of the most common requests heard in a yoga class is hip openers today please. This request is usually followed by the other half of the class groaning. We love to hate hip openers yet our bodies crave them and often feel lighter and more open after — for good reason. The majority of us sit for most of our days, shortening the hip flexors at the front of the hip (psoas, rectus femoris, sartorius) and tightening the hip rotators (piriformis, obturator internus, gamellus, to name a few).
A Look Inside the Hip
The hip joint itself is a ball and socket type joint with the head of the femur (thigh bone) sitting in the acetabulum or socket of the pelvis. A variety of muscles attach into the femur starting from the pelvis itself, the lumbar spine, the sacrum, or other parts of the femur. Hip openers could affect any of the muscles surrounding the hip depending on the position of the joint at the time of the pose.
In general when we stretch or open a muscle we are lengthening its position, moving the two attachment points away from each other. This is easy to assess with linear muscles like the psoas which attaches from the front of the lumbar spine, crosses through the pelvis and attaches to the head of the femur. If we flex the hip forward we are shortening the psoas, bringing the two attachments of the muscle closer together. If we extend the hip backwards (such as in the back leg of Pigeon pose we are opening and lengthening the psoas. The effect becomes greater in King Pigeon pose if we assume an upright posture with our spine so that we lengthen the upper attachment more. In this example we can also rethink our definition of hip openers. Suddenly, poses with a bent knee where we rotate the hip are not the only way to open our hips. If the psoas attaches into the femur, and a shortened psoas tightens our hip (not to mention the affect it has on our low back) then poses like Warrior / Virabhadrasana or Half Moon / Ardha Chandrasana become hip openers too.
Rotate to Open a Rotator
The rule of how to open a muscle becomes less clear with the hip rotators where the angle of the joint actually affects the action of the muscle. For example, the piriformis muscle attaches from the front of the sacrum to the back of the femur. It acts as an external or outward rotator of the hip. Except if the hip is flexed, then it assists in abduction or sideways movement of the hip. So to follow the rule of opening we would want to internally rotate the femur, flex the hip and adduct or bring the femur towards midline. This can be achieved with the top leg in Marichyasana (sit with your left leg extended, bend your right knee and step the foot across your left thigh so that the femur is flexed, adducted toward midline, and gently internally rotated.) Other hip openers don’t seem to follow the rule of opening. We often externally rotate the hip to stretch the external rotators of the hip. Huh? The reason this works is because we typically flex the hip at the same time.
Use Your X-Ray Vision
To understand how hip openers work we have to picture the position of the muscle. Let’s picture the obturator internus muscle, a close friend of piriformis. It attaches from our sitting bone or ischial tuberosity to the greater trochanter of the femur, a bony outcropping on the side of the hip. We can feel both of these pieces of bony anatomy. Our ischial tuberosities can be felt when sitting, they are the bony bits under the flesh of our buttocks. Our greater trochanter can be felt by first finding the top of our pelvis by by placing our hands at our waist, firmly pressing in and down until we feel a ledge. This is our iliac crest. Slide your hands down and with your thumb you will feel a bony prominence that is the femur. You can feel it move by slowing rotating the hip in and out. So now we can feel the attachment points for the obturator internus, between the ischial tuberosity or sitting bone, and our femur. From this observation we can see that in a neutral position the muscle wraps around the hip. So if were to flex the hip, the ischial tuberosity scoops under thus increasing the space between the two attachment points and increasing the wrapping distance of the muscle – hence lengthening the muscle. This is why a simple squat (using the term simple lightly) can stretch our hip rotators and can be one of the reasons Westerners find it so challenging to achieve.
Opening Our Hips to Open to Possibility
Since there are many muscles in the hip with many functions depending on the demands we place on our body, keeping these muscles supple can help us in ways that may not seem obvious at first. Hip openers may help us attain a standing pose we’ve been struggling with, or they may help us get down on the ground easily to play with our kids or our kitten. Traditional yogic thought attributes many healing properties to hip openers from organ issues to sexual dysfunction. So if you are one of the groaners when hip openers are suggested, perhaps pause to wonder if they could be helping you in ways you weren’t even aware.
