Thursday, April 14, 2011

Step 3: Use a Lumbar Support

The Desk Warriors Guide to Building a Healthy Back! 3/10

Now that we've learned that there is no one "ideal" sitting posture and that we Desk Warriors must have a repertoire of tolerable postures. Our repertoire should include mostly postures that allow for the spine maintain its natural curves, specifically the lumbar curve.

Some chairs set you up for failure right from the start.

The above chair has no lumbar support and will have your arse lower than your knee, creating flexed, weakened, painful spines. When working with these chairs it is essential to arm yourselves with a weapon. This weapon will spare your spinal capacity for more important tasks like playing with your children, doing yard work, or walking the dog.

The Weapon I speak of is a lumbar support and it comes in many shapes and sizes. Before I elaborate on those, lets examine why a lumbar support is essential to those interested in their spinal health. Lumbar supports should be a part of any Desk Warriors arsenal because they help place you in a more natural seated position. Rather that eliciting a great muscular effort from your hip flexors, abdominals, obliques, and lumbar spinal muscles to maintain your lumbar curve, (placing compressive load on the spine in a flexed position) we can rely more on our passive tissues in a less compressed manner. This means you'll be able to sit longer without detriment. You can type the rest of that paper, send out those last few e-mails, make those last calls etc... You'll be a more productive worker with less damage to your spine.

Granted we want to sit less for a multitude of health reasons, we still sometimes need to sit for prolonged periods and sitting with a lumbar support will help that cause.

A good lumbar support is one that will allow you to maintain a similar lumbar curve to when you are standing with good posture. This should be the position in which you are standing tall and that your core muscles are most relaxed. Go ahead stand up and find this position. You should be able to go in a 360' wrap around your spine, feeling all the muscles and not getting too much tense feedback, especially in the muscles of the lumbar spine. If you can't stand without tensed core muscles, we've got a problem. This lack of muscle tone indicates a lack of compressive force and thus, a posture that can be tolerated for longer durations.

Now, lets visit the lumbar supports and their various shapes and sizes. As stated above, the right lumbar support for you is one that will help you achieve the amount of lordosis that you naturally possess when standing. Some Desk Warriors may require more support than others. For others, too much support may be just as uncomfortable or more uncomfortable as no support at all. Though there is some individuality in the needs for lumbar support, the idea of supporting the lumbar spine when sitting is still valid and should be pursued.

Lumbar supports come in various shapes and sizes as evidenced on I recommend the contoured variety, like the Carex Lumbar Support Cushion. They embrace your entire low back and apply a bit of support from the sides. I have personally tried the McKenzie lumbar support and McKenzie air support and found them to be flimsy and less supportive. I personally use a Welby foam lumbar support that is very similar to the Carex variety. They can be purchased from time to time at Aldi (the grocery store). I haven't found them online. Look for a support that wraps around your chair so that it will stay in place. Versatility is also something to consider. Remember, changing positions often is desirable. Your lumbar support can be a tool to facilitate this.

You don't have to go out and spend cash to use lumbar supports. You can simply roll up a towel, use a small pillow, the dog, a book. I don't care what you use, but you should use something. I do however recommend buying a lumbar support; one that you enjoy and will use often. I don't anticipate people using rolled up towels often. The less work you have to do the better, and the more often you use it while sitting the better. Buy one for work, one for home and one for the car. Heck, if you are really orthopedically mangled, you may even want to sleep with one. McKenzie sells 180' spinal support wraps that will help preserve your lumbar spine for our side and back sleepers. Consider this an option if lower back pain keeps you awake at night, or if resting does not alleviate your back pain resulting from a days work.

So get out there and get yourself a nice lumbar support and use it! Spare your spine for more battles at the desk!

Thursday, April 7, 2011

Step 2: Sit Better!

The Desk Warriors Guide to Building a Healthy Back! 2/10

By reading part 1 of The Desk Warriors Guide to Building a Healthy Back, we know that sitting for prolonged periods is something to be avoided. But what are we to do when sitting can't be avoided? After all, our jobs, our livelihoods are now spent hunched over computers. We can't all earn a living on our feet like pro-athletes, dancers or even bartenders for that matter. We have to sit at a desk and work.

This begs the question, what is the most optimal seated posture?

I will first address the myth about "proper" posture. When we sit with "proper" posture, our feet flat on the floor, our knees and hips at 90', the spine long and upright; the head and chest up and our lumbar curve maintained we are actually damaging our lumbar spines. This may be aesthetic sitting posture or proper school boy/girl posture, but according to my man Stuart McGill it is only tolerable for 10 minutes max and should not be attempted further.

"Ideal" Sitting Posture Try to sit unsupported like our man with the "ideal" posture for 10 minutes...

If you take us up on the "ideal" seated posture challenge, what will happen is you will engage your core muscles to the point of fatigue. As discussed in the previous post, engaging the core muscles results in a shortening of the muscles, thus spinal compression. The hip angle of 90* with core compression results in increased compression of the spine, thus increased intradiscal pressures (pressure on your discs). Take a moment to stand up tall and feel your core muscles. Feel the muscles in your lower back and the muscles that surround your waist. You shouldn't feel a great deal of muscular tension. When standing upright, you are designed to elicit the smallest amount of muscular effort. The curvature of your lumbar spine bears the brunt of your weight and only perturbations during movement should result in greater core muscular activity.

So when engaged in prolonged sitting, we want to find ourselves in a position where like standing, the core musculature is at a minimal tone or effort. The typical seated posture or worse, the forward bending seated posture compresses the vertebrae in a manner that sends the disk posteriorly (backwards) This causes a posterior annulus strain of the disk while (center of the disk bursting through the annular layers of the disk leading to bulging and eventually herniated discs). We now know that the outer layers of the annulus fibrosus are innervated (containing nerves) This means that delamination, as occurs when the nucleus of the disc bursts through annular layers (bulging disc) causes pain without impinging on the larger sciatic nerve as previously thought. Further prolonged sitting leads to creep in the posterior passive tissues, which is essentially loosened spinal ligaments allowing for more shearing movement on the spine. This is bad. Think of the mechanism of grating cheese, that is anterior posterior shear, not something you want going on in your low-back.

Now we've deduced that sitting with "ideal" posture or a hip angle of 90* is not a good long-term seated posture.We guessed that leaning forward and increasing the hip angle is even worse because it accelerates the rate of all the above jargon happening in your spine (as viewed below or here). So let's get to the meat and potatoes. How can we sit longer and not destroy our spines and health in the process?
The above T-bone steak looking thing is an illustration of your vertebral discs. The center or nucleus migrating posteriorly as intradiscal pressures increase in various postures.

Now you smart ones out there probably took a good look at the above picture above and hypothesized that since
laying down has the least amount of intradiscal pressures via relaxed musculature, that a more reclined posture is

You would be correct. However, a back angle of anything less than 135* can't really be considered sitting since you are closer to laying down. Assuming we have to be at a desk/work station in a seated position, the ideal posture is one in which muscle activation is lowest via support (back of chair or lumbar support), maintenance of the normal lumbar curve and one in which we can change position easily.

The reason we need to change positions easily and regularly is to not overload any one tissue. Tissue loads need to be migrated from tissue to tissue in order to minimize the accumulated microtrauma of any one tissue. Think about it, you fidget for a reason. You are spreading the microtraua from tissue to tissue. McGill recommends changing postures very often. Atleast every ten minutes.

The chair is not helping the situation. Chairs are designed by architects, not biomechanists. Ideally, you would want a chair with a great deal of lumbar support. The Nottingham chair is one that supports the lumbar spine and aims to keep a posture more congruent with standing, thus sparing the spine. Standing desk stations are also a great way to preserve the spine. But yes, the Nottingham chair is expensive and unstylish and standing desk stations have their problems as well.

So when forced to sit for long periods of time. We want a chair that supports the entire back, rather than doing all the work ourselves via the core musculature and contributing to spinal compression in a flexed posture (contributing to discogenic pain). We want to be able to mimic normal standing posture as best as possible so a chair that supports the normal lumbar curvature is essential. If your work chair does not do this, simply buy a lumbar support. Arm rests also alleviate spinal compression, so use them when you get the chance. Most importantly, we want a chair with the ability to recline. The more the better. The optimal seated position would be in a lazy boy, but as most desk warriors aren't afforded this luxury, we must aim to achieve this recumbent position via lumbar support and reclining our chairs. Again, I reiterate that any position must be changed eventually to promote circulation and to spread the microtrauma to various tissues, thus our reclined lumbar supported position must to be changed regularly.

The least compressive the posture, the longer it can be tolerated. So Desk Warriors, arm yourselves with an arsenal of appropriate desk postures. Change the angle of your back via more or less lumbar support or varying degrees of reclination. Shift your weight to your right, then your left. Sit with your legs crossed, left and right. Cross your legs with your lean on. Essentially be mindful of maintaining your neutral lumbar spine while shifting into a variety of comfortable positions.

This stance on postural shifting can also be applied to sleep. No one sleeps in any one position and they shift subconsciously. They do this because it's our way of our body spreading the stresses to different tissues as we should do when we sit, stand, lie etc…

In conclusion, the ideal posture for prolonged sitting is a reclined ~135 back angle posture where our natural lumbar, thoracic and cervical curves are preserved. However, we learned that after a certain exposure, no position is safe and that we must find a variety of Desk Warrior poses to serve our productivity needs.

Callaghan, J.P., and McGill S.M. (2001) Low back joint loading and kinematics during standing and unsupported sitting. Ergonomics, 44 (4): 373-381

And of course the books cited in Step 1: Sit Less

Saturday, April 2, 2011

Step 1: Sit Less!

The Desk Warriors Guide to Building a Healthy Back! 1/10

The International Journal of Obesity found in 2001 that Australian men working full-time on average spent 9.8 hours sitting in a chair daily. Since we Americans work more than most any other country, I'd estimate we sit perhaps 10 hours per day on average. This may seem like a lot at first but think about ones typical day. We wake up and may sit down for breakfast, if not we sit in the car as we drive to work. Most of us spend the majority of time seated at work. We sit down for lunch and dinner. The drive home is spent sitting in traffic and finally we crash on the couch to watch some night time television or to check our Facebooks. So now 10 hours per day doesn't seem so outrageous. 10 hours per day is 3,650 hours per year, or 42% of our day!

This “trend” of sitting for such long hours on a daily basis is surely not in line with our evolution. Accountants and I.T. Professionals are rather recent vocations. Sitting through rush-hour traffic and sitcoms are also new endeavors. We are evolving from hunter-gatherers who spent very little time sitting and when they did, they sat like this to amorphis blobs that vegetate in front of computer screens. (see below)

So why is all this sitting a problem for our backs? Why does it contribute to pain? To understand this we must understand a little anatomy.

When we stand with ideal posture, the curve in the small of our backs (lumbar curve) enables us to stand with a minimum of core muscle activity. Small amounts of core muscle activity while at rest (lying, sitting, standing, walking) is a good thing, because all core muscle activity compresses the spine. Too much compression of the spine will require a large percentage of your backs daily tolerance to loading.(which we'll talk about later)

You see, a muscle can only contract, or shorten. The muscles that support the spine go from your ribs to your hips or from the vertebrae of the spine itself to your hips and femur. Thus when these muscles contract, they shorten effectively compressing the spine. This is all fine and dandy when we are doing athletic moves and need a stable spine, but when we are simply sitting and resting, we want minimal spinal compression thus we want our normal lumbar curve.

When we sit, our lumber curve is attenuated, even in the best of chairs. Thus, we lose our lumbar curve and contribute to spinal column compression via excess muscular activation. Excessive core activation overtime via sitting or poor posture will... as my man Dr. Stuart McGill, the leading spine researcher in the English speaking world states A.) Decrease our work capacity B.) Degenerate the spine more rapidly C.) Exacerbate pain and disc problems. D.) Increase in intradiscal pressure when compared to standing postures.E.) Increase in posterior annulus strain. (Thats your disc trying to herniate or bulge backward)F.) Creep in posterior passive tissues which decreases anterior/posterior stiffness and increases sheering movement. (less stabile/more painful)G.) Posterior migration of the mechanical fulcrum which reduces the mechanical advantage of the extensor musculature (resulting in compressive loading).

In Layman's terms, prolonged sitting forces the spine to bend forward. See the spine above, picture it bent forward. The front of the vertebrates compressed together, pushing the center (nucleus) of the disks backwards. This is how we get bulging and herniated discs without traumatic injury. Also, the ligaments that support the vertebrae on the back side are elongated. They adapt to this elongated position. This is referred to as ligamentous creep. The ligaments are stretched out and your spine is now less stable. We want a stable lumbar spine and good movement in the thoracic or mid-spine and the cervical or neck regions.

When we sit, our quads (muscles in front of our legs) and our hip flexors (deep muscles connecting spine-hip-femur) are in a shortened state. Since we are very adaptive organisms, our bodies adapt to this shortened position as the new norm. The end result is short, tight muscles. These short tight muscles then pull our hips into an anterior-tilt (forward). (IMAGE) This is a problem because our lower backs compensate.

Our lower backs also will compensate for the anterior, or forward head position as seen below. This problematic posture loads the neck muscles much more, resulting in increased compression and thus neck pain, cervical disk herniations, arthritis, pinched nerves, shoulder pain and other problems related to nerve impingement that will manifest elsewhere in the body. Now this forward head position throws off our spinal equilibrium. The neck is flexed forward, the mid-spine is stable due to the articulations with the ribs. The mid-spine is less mobile and therefore our lower backs will again pick up the slack and take on the extra flexion. This is PRECISELY WHY YOU SHOULD NOT LOOK UPWARDS WHEN SQUATTING!

So when we have tight, short muscles in one area that inhibit proper movement patterns, other joints must pick up the movement slack. In this case, the joints directly above and below our tight hips pick up the slack. These joints of course would be the five vertebrae of the lumbar spine and the knees. Let's think real quick of the top 2 complaints that would lead one to see an orthopedic specialist. YEP, you guessed it achy LOWER BACKS and KNEES! The sitting posture tightens the anterior muscles and subsequently elongates and weakens the posterior muscles, leading to poor motor control and decreased tolerance to injury.

Hopefully we understand better why sitting is awful for us. It makes us shorter, weaker, less attractive and more prone to injury and pain. But how can we expect to sit less? Our livelihoods now depend on our ability to sit for extended periods of time. This 10 part series on spine health will cover the best ways to sit all the way to strengthening and rehabilitating your jacked-up spine.

O yes, and my references...