Poor Posture and Pressure on your Spine
Freddie Mercury was right: we’re under pressure. Nothing can be truer when it comes to your spine. It’s because of simple physics: the pressure or load on your back increases as you move away from a neutral posture. Here are the numbers: Standing straight puts 100mm of pressure on the intervertebral discs of your spine; add a forward bend while flexing or rounding your back and you’ve more than double the pressure, or 220mm. Can you see now why reaching your toes in Uttanasana or any standing forward bend before you’re ready isn’t worth the potential harm to your back?
What poor posture means to the ongoing health of your back?
Over time, poor posture causes the discs between the vertebrae to wear down and lose their ability to cushion and act as shock absorbers. The discs are pushed out towards the back from their normal position which causes bulging or herniated discs. These bulging and worn out discs can cause a more serious problem by increasing the pressure on the spinal nerves and the spinal cord itself. The result is pain in the legs, including sciatica, arms, shoulders, and neck, and problems with muscle innervations, movement patterns and the sensation of temperature, pressure and pain.
These same problems can be worsened when sitting, believe it or not. Sitting, in contrast to standing, actually increases the intradiscal load compared to standing; spinal pressure “sits’ around 140mm pressure. If you slouch (I’m talking to you desk slouchers!), spinal pressure increases to 190mm; add some weight and you’ve put a whopping 275 pounds of pressure on your spine. This is why in certain methods of yoga like Iyengar students learn standing poses before sitting ones as a general rule as they’re considered more advanced.
Sitting for long periods of time can definitely cause back pain or worsen an existing back problem. Sitting is a static posture that increases stress on the entire back, shoulders, arms, and legs, and especially the muscles of the spine. Slouching overstretches spinal ligaments and surrounding structures of the spine and nerves, blood supply is interrupted and the back muscles are overstretched.
If you’re not a yogi yet but find yourself slouching or sitting for long periods of time during the day, your yoga can be as simple as doing the following:
Getting up periodically to stand up and take the pressure off your spine
Sit back into your chair so your back is supported. In yoga postures, ground evenly into your support and allow your spine to straighten up
Use a lumbar roll between your lumbar or lower back and your chair. To judge the proper size of the roll, sit back in your chair, place your forearm behind your lower back between it and your chair and lean back. Your forearm is approximately the size of a lumbar roll. This works when driving too.
Move! Joints don’t have much blood flow. Joints get nutrition in and waste out by physical movement. Move freely in your chair instead of sitting still for hours at a time.
For you yogis, body awareness is key to minimizing the pressure on your back. I’m not saying never practice a forward bend or a seated pose but rather know how to practice them safely. Even a seemingly friendly pose like Savasana can do harm. Sure, while lying down you’re at the lowest end of the spinal load spectrum at 25mm. As a teacher, I ask my students to roll to the side before sitting up not simply to avoid feeling dizzy and lightheaded but also to reduce the pressures on the spine. For the record, resting on your side applies 75mm pressure on your back, which is quite a bit less than pulling yourself straight up from lying flat on your back.
So, the take home message is: do the work in other poses which don’t load the spine first to lengthen your leg muscles and hamstrings, and strengthen your back before you throw yourself into a forward bend. Realize which types of poses are right for you. Gentle flexion of the spine isn’t for everybody and that’s ok. Once your body is ready, you’ll be reaping the benefits of practicing Uttanasana instead of causing harm to our back.
Understanding the Sacroiliac Joint
Asana Anatomy-Understanding the Sacroiliac Joint
Controversy does not often strike the yoga community. Non-harming, truthfulness, and loving kindness are not very controversial concepts. Yet the poor, barely mobile, sacroiliac joint has become the center of a yoga debate – to square or not to square the hips. Ok, so it is not as racy as a celebrity feud, but it may affect your personal yoga practice.
Let’s dissect this joint.
The two sacroiliac joints (SI joint) are formed by three bones: the triangular sacrum bone, and the two wing like bones of the pelvis known as the ilium. Each iliac bone (one half of the ilium) comes in contact with one side of the sacrum, forming two SI joints. This connection is like three puzzle pieces fitting together known as form closure. Form closure creates stability, keeping the pelvis together in one unit. The SI joint itself is shaped like a boomerang with two arms at 90 degrees to each other. The upper portion lies in an up-and-down orientation and the lower portion lies in a front-to-back orientation. The surface of the joint is covered in coarse cartilage, adding friction and contributing to the force closure.
The sacrum moves in nutation (forward) and counter nutation (backward) in relation to the ilium. The sacrum can move only on one side, like in lifting one leg, or both sides, like when we move from lying to standing. This movement is very small, amounting to 1 or 2 mm of motion in either direction. As we age, the sacrum becomes wedged increasingly forward, but this doesn’t fully happen until we reach our 30’s. This wedging increases the resistance to shearing (twisting) forces across the sacroiliac joint. Herein lies the problem. The SI joint is a joint that is intended to provide stability for the pelvis, and is not built to move.
The SI joint has another mechanism of stability – force closure. This is the stability created by the action of the core musculature that has attachments into the SI joint – namely, the muscles of the pelvic floor, and the transverse abdominis. Conveniently, we can access these muscles through the activation of the bandhas or energy locks in yoga. In mula bandha we imagine a subtle lifting up of the muscles we use to control the flow of urine. In women, activation of this musculature has been shown to provide force closure for the SI joint. In uddiyana bandha, we draw the lower belly in and up, activating the transverse abdominis muscle. For this version, the scooping of the lower belly needs only to be subtle, and slightly flattens out the lower abdomen.
Hip Opening or Sacroiliac Opening?
Many of us identify ourselves as having “tight hips”. For many, this means a lack of external (outward) rotation at the hip joint. Using the example of Virabhadrasana I or Warrior I pose, our front hip is in a flexed position with toes pointing straight ahead. Our back foot is on the floor at a 45 degree angle, and in order for the points of our hips (our iliac crests) to face toward the front of the mat, our back hip needs to extend, and externally rotate. If we look deep inside we see that these actions require our sacrum to nutate forward on the side of the lead leg, and counter nutate backward on the side of the rear leg. If the rear hip resists external rotation in order to square the hip points forward a twisting or shearing force is introduced across the SI joint. Over time this can lead to irritation, hypermobility, and dysfunctional firing patterns of our pelvic musculature.
This situation is an opportunity to practice ahimsa or non-violence towards our SI joints. There are a few ways you can diminish the shearing force across the SI in standing poses. The first is to take a slightly wider stance, opening your feet to hip width (rather than heel to arch or heel to heel). This enables your pelvis to comfortably square forward. Another option is to keep the feet as they are and simply allow your pelvis to be slightly open to the side of your mat. That’s right, let go of the desire to perfectly square your pelvis forward. Instead, imagine the hip bone in its socket, outwardly rotating. Keeping that rotation, tuck the tailbone under slightly, creating room in the front of the hip. You may find that this provides more freedom of movement and may naturally square your hips further. In standing and seated twists, be sure to engage the muscles of the pelvic floor (mula bandha) to support the SI joint before twisting.
When we step back for a moment and acknowledge the true purpose of our yoga practice, suddenly trying to make our bodies fit a mold doesn’t make much sense. Being more forgiving and accepting of our bodies limitations enables us to go much deeper into our yoga practice and experience the joy of yoga safely. Now that doesn’t sound controversial at all.