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 amazon.com. 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!

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

optimal.

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