Slouched Posture: Efficient or Not?

Inspired by Todd Hargrove’s post at BetterMovement.org: “Is “Efficient” Movement Unsafe?

The Back Extensor Group of Muscles

I remember reading that good posture was the most energy efficient way to stand and sit. But why does it seem to take so much more energy to keep the spine straight than to slouch, especially with fatigue or illness. If energy efficient means using the least amount of energy to perform work then at first glance, slumping with rounded back does seem to take less energy because the back extensors, a large group of back muscles, slack off from straightening the back and let the weight of the upper body hang passively off spinal ligaments and joints. But is the spine well suited to supporting this much dead weight by itself? The short answer is “NO” because the spine has inherent flexibility that allows it to bend when needed for everyday activities. The fact is that by itself the normal spine cannot be both flexible to allow us to bend down to tie our shoelaces and inflexible enough to completely support our bodies. A fused spine can’t bend and therefore doesn’t need stabilization, but a normal, flexible spine does need the stabilization that is provided by the balanced action of two antagonistic groups of muscles—the back extensors, which bend the spine backwards (and keep us erect), and the front abdominals which bend the spine forward. For ideal posture the extensors and flexors act in concert to stiffen the spine in as close to a vertical position as the natural curves allow. This is the spine’s most stable and least stressful/damaging upright position and results in even distribution of compressive forces on intervertebral discs.

When the back is excessively rounded forward, discs are unevenly stressed, and over time their outer layer or annulus prematurely develops tiny cracks that cause loss of moisture and disc height, which causes spinal instability, increased pressure on facet joints, bone spur formation and stenosis. A rounded back also causes an imbalance of head and upper body weight. Optimal distribution of body weight is important for our ability to stand upright. Moving around on two legs is precarious to begin with. And if the ten to fourteen pound head juts out in front of the body because the top of the thoracic spine curves forward, and the upper chest and back, shoulder and arms also curve forward, it’s more difficult.

There is already a natural imbalance of weight due to the rib cage chest area extending out front of the thoracic spine,

Balanced(which has a natural kephotic (posterior) curve to counterbalance the rib cage (see balanced posture at left) and this weight imbalance causes a constant forward bending pressure on the spine that must  be resisted for the body to stay upright.

 

 

 

 

With excessive rounding of the upper back, the body must realign itself to keep from falling forward. One of three strategies is used:
Flat_Back

 

1. The pelvis rotates backwards, trying to pull the upper body upright, and pulls both the lumbar and mid thoracic spine flat. But since the upper back and head are still held forward of the torso, and there’s no counter-balancing curving of weight to the back, the entire body leans a little forward, not so much that one would fall over (unless trying balance exercises), but enough to have difficulty flattening the entire back and head against a wall without extending (bending slightly backwards) the back. see Flat Back Posture

Sway_Back1

 

 

 

 

 

 

 

2. The upper torso shifts backwards in a long, rounded curve that is also counterbalanced by the pelvis shifting forwards. See Sway Back Posture.

 

 

 

 

 

Kephotic_Lordotic1

3. The excessively hunched upper back is counterbalanced by the abdomen, which pooches out in front because of an excessive inward lordotic curve of the lower back. Against a wall, the upper back and butt may touch, but there’d be lots of space between wall and lower back. See Kephotic-Lordotic Posture.

 

 

All three strategies/postures produce their share of sore backs and necks.

 

 

 

 

Balanced Posture

Now, getting back to the subject of “Efficient Movement.”  A better definition for “efficiency” would be “The least energy used to achieve the best possible result.”  The back extensors must be engaged to stabilize the spine, so that body weight and other forces are borne with vertebra stacked vertically, one on top of the other and the forces are spread evenly on discs and ligaments. When the back is as straight as possible, given the natural curves,  body weight is close to being balanced around the spine. The vertical black line (the center of gravity) in the posture illustrations, represents equivalence of weight in front of and behind the line. When weight is balanced, posterior muscles like back neck muscles and lower back muscles, as well as hip extensors (hamstrings) (depending on the type of faulty posture) are not over-worked. But also front postural muscles like neck flexors, abdominals and hip flexors are not under-worked and weak.

In Todd Hargrove’s words: “any local gains in energy efficiency from “floppy joints” are more than offset by a general loss of energy efficiency that comes from poor alignment of the bones and inadequate stabilization of the joints….In other words, valgus knees (knees collapse inward), rounded backs, and overpronated feet (foot rolls inward and arch collapses) are not actually energy efficient at all, because they sacrifice the stabilization and proper bony alignment which is the key to efficient movement and posture.” Yes, it feels easier to slouch especially when one is tired or not feeling well. Add a chronic illness, and it seems like there’s little energy left to stand tall with good posture. But it is so worth the effort because the strength and balance of postural muscles is preserved and the chances of postural neck and back pain are greatly reduced.

Examples of Poor Posture

Posted on June 22, 2012 by Rochelle

The Thinker by Auguste Rodin, one of the most recognizable sculptures in Western Culture, is an example of really bad posture. I’ve added the skeleton to show that his rib cage sags and constricts his breathing. His lower back is rounded, which puts excessive, one sided, pressure on the intervertebral discs of the lumbar spine. His posture though, is not the worst  I’ve seen. He doesn’t sit on his lower back like so many  young people. He sits squarely on his sitting-bones or  ischial turberosities.

 

Gwyneth Paltrow is a beautiful woman but tends to have swayback posture. In Duets, a marvelous  movie combining multiple story lines with love and karaoke,  Paltrow exaggerates her poor posture even more to portray a gawky, young innocent, who melts the heart of her long absent karaoke-hustler father, played by Huey Louis.

 

 

 

 

 

 

 

 

 

 

 

 

 Lily Cole, an English model and actress, tends toward a rounded back.

 

 

 

 

 

 

 

 

Myley Cyrus, like many teenage girls, tends to have curved forward shoulders, rounded back, and depressed chest.

 

 

This is approximately what my posture looked like before I realized that slouching had caused my chronic neck pain. Unfortunately, none of the many doctors or the four physical therapists  I went to for help ever mentioned my poor posture as a possible cause of neck pain. One PT commented that my shoulder blades weren’t working right, but he didn’t say why and didn’t give me exercises to fix it. (Or maybe he did but I was clueless at the time. In my defense, I had a debilitating stomach illness, was in a lot of pain and my neck felt so weak I could barely make it to PT sessions. ) Regardless, I’m still amazed and very disappointed that all these professionals could not help me. I had to find my own way.    See fixtheneck.com

Neck Pain From Using Cell Phones, Tablets and Laptops

My son, a personal trainer, told me that one of his clients was complaining of neck pain. He asked her how often she used her new Kindle Fire. It turned out that excessive tablet use coupled with poor posture was the source of her pain.

When using a cell phone for text messaging, anchor your upper arms close to your body and bend your elbows to raise the phone closer to your face. Then lower your eyes, instead of tilting the head down, to see the screen. Avoid bending the neck forward and down; if you still must tilt your head, use the top-most “hinge” joint of the neck. But do try to have your arms and eyes do most of the work.

A handheld tablet with keyboard seems like it would be very awkward to type with (needs thumb-typing or one-handed typing). So a tablet is probably placed on a surface for that. My son says the Apple Ipad has dictation capability; maybe typing is not so necessary. Then there’s the stylus, a one handed implement for note-taking. [update: one needs to speak very clearly for Ipad dictation to be accurate (good speech therapy for those who need it!). My son bought a case that tilts the Ipad up so he doesn’t need to tilt his head down as much. He also says a case is available that comes with a separate keyboard and also elevates the Ipad. Essentially the Ipad becomes a desktop.]

Typing on a laptop rather than a tablet should be easier on the neck, as long as it is on a surface like a table top, which it seems most people do. But still the monitor cannot often be raised to comfortable eye level so see people bending their necks down all the time. As with cell phones, it is better to roll the eyes down. Better still would be if the laptop screen could be separated and hung at eye level. (Do any laptops come with separatable screens?). For now I am sticking to my desktop computer. At least the monitor can be adjusted to a comfortable height, which for me is just below eye level, so I can see it in the reading part of my eyeglass lenses without tilting my head up. (First I adjust my chair height so my feet rest firmly on the ground and my lower legs are perpendicular to the ground. If the monitor needs to be higher, I use a large book or two to raise the monitor further.)

For an informative video on improving sitting posture to avoid neck and shoulder pain due to prolonged desk work, computer and mobile device use; see Sitting At Your Computer on Dr. Robert Kelty’s Chiropractic Wellness Center Website

 

Droopy Shoulders Syndrome

An exception to use of part 1 of Fix the Shoulder Blades Exercise is a condition called Droopy Shoulders Syndrome (DSS) that is mainly present in women with low set, steeply sloping shoulders and long, swan necks. Their collar bones (clavicles) slope down at the outer ends rather than the usual slope up. In lateral neck x–rays, all of the 7th cervical vertebra, the 1st thoracic and sometimes part of the 2nd are easily seen when usually the shoulders prevent visualization. Pain in neck, shoulder, arms, hands is aggravated by downward traction on shoulders and relieved by propping up the arms, and may involve Thoracic outlet syndrome. In DSS the shoulder blades are already held too low on the back and don’t need to be lower. Maintaining a slight lift of the shoulders so they are more squared helps. Part 2, Pinch the Shoulder Blades Together is still useful if shoulder blades are wider apart than 4 inches. Consult your physician or physical therapist. See “The Droopy Shoulder Syndrome,” L. Clein, and “The Droopy Shoulder Syndrome” by Swift and Nichols]

My neighbor had neck, shoulder and arm pain (around the biceps muscle). Her shoulders were obviously very sloped down, and her neck seemed very long. I urged her to see a physical therapist, which she did. Luckily the head physical therapist (not the assistant) knew how to help her. The advice was to keep her shoulders raised a bit. I recently talked to her and noticed her shoulders are more squared and she says her pain is gone. It has only been recently that I realized the clavicle (collar bone) in front in most people slopes up toward the outside ends., showing that the shoulder blades, which are attached to the clavicle near the shoulder joint are held a little higher.  But hers are straight horizontal. Wish I’d noticed whether her clavicles were downwardly sloped before she got the therapists advice to lift her shoulders.

Poor Posture Everywhere

Having experienced and then overcome the chronic pain that poor posture caused me, I tend to think that everyone with poor posture will eventually develop some form of musculo-skeletal pain problem from it. But like a former smoker who rails against smoking, I tend to be over zealous.  I can’t help but see examples of poor posture; like the tall slender preteen in line at the grocery store with her father. From the looks of her uniform, she’s just come from playing a sport like soccer, so she’s not a couch potato, but her high thoracic hunch and rounded shoulders is a mirror image of her father’s posture. I get to wondering how bad his neck pain is, and how bad hers will be in the future.  Or there’s the checker, a young woman with the long, rounded swayback, exceedingly curled-in shoulders and a caved-in chest. I have this desire to snap their photos and show them what I see. I want to ask them, don’t you know your posture is ugly, and you’re messing your body up? But of course, it’s not my place to say anything. I know what comes of butting in. And really, these people don’t look like they’re in pain. (What does a person in pain look like?  When I was in the midst of my pain-filled days, could you see the pain in my eyes?) In fact some studies have been done (I have to find the references) that found that many people with poor posture don’t have spinal pain. But on the other hand those with back and neck pain, often do have poor posture. So there’s a question of what comes first, the injury, whether acute or repetitive, that “caused” the pain or the poor posture? But as I’ve said before, my posture was bad from the beginning. It was only after a bad neck strain at age 21 that my neck pain began and never went away. So it would be easy to say that the bad neck strain and accelerated arthritic deterioration seen in my MRIs were the cause of my worsening neck pain. If I hadn’t overcome that neck pain by improving my posture and strengthening shoulder blade stabilizers, I wouldn’t have known that the root cause was poor posture, and not the spinal arthritis.