The Importance of Posture

(Originally posted on bcotoronto.com on June 7th, 2012)

The Importance of PostureI don’t know about you but after nine weeks of diets and nutrition I think I’m ready to talk about a difference topic. So let’s talk about a more traditional chiropractic topic, Posture. When we were young, our mothers always told us to sit up straight but who really listened? Well, I hate to say it but they were right (just like so many other times). Posture is extremely important in life. Our skeletal system is, quite literally, central to our daily functioning.

Improper posture is very rough on our entire body. Almost every system is affected in some way. There is tremendous strain placed on the muscles supporting the joints. The best example of this is the group of muscles called the Erector Spinae. They run up and down the length of our spines and when we have hunched shoulders or a rounded low back they try to compensate for the pull of the posture and end up being very tight and often painful. On the other side of this equation the muscles on the opposite side of the improperly oriented joint are shortened and, over a period of time, lose strength and tone. This makes them weak and unable to perform when we need them too. This combination of spasms and weak muscles can lead to many common conditions ranging from headaches to rotator cuff injuries.

This stretch and strain due to poor posture does not only affect muscles. Ligaments surround all joints and help to support them and limit potentially harmful movements. When a joint is improperly aligned the ligaments on one side are stretched just like the muscles. In this case they do not become tight in spasm. When a ligament is stretched over a long period of time it begins to lengthen so that it is able to respond to movement when it is needed. Once again, the other side of the joint goes through the opposite reaction. Ligaments on the side of the joint not being stretched will begin to tighten over time as they are “too loose” in this position. This means that the longer we stay hunched over the harder it will be to straighten back up again.

The tissues surrounding the joints are not the only things that change due to improper posture. The joints themselves will alter their structure due to the pressures being put on them. Just like two rocks rubbing together, their surfaces will eventually wear away to conform to each other. I have said this many times before but bone is constantly remodeling itself to conform to the pressures being place upon it. In this way a joint that was once perfectly shaped to support and function in good posture will eventually change and alter to accept this new position. Now you may be thinking that this solves the problems associated with posture but the muscles and ligaments will still be stretched and spasmed around this altered joint and this new position is actually very precarious. The pressures due to gravity and the loads we carry are very important if you remember back to our talk about Osteoporosis. They determine where the strength of a bone will be oriented. Over time, poor posture will lead to changes in the strength of our bones which will take away from the optimal function of the bones in the long run.

Bone may alter itself and remodel with time but cartilage does not. The pressures on misaligned joints will wear away at cartilage and bring about degeneration within the joint. This leads to arthritis within the joints.

The most common position of improper posture is slouching shoulders and leaning forward which significantly alters the mechanics of the ribcage. As we were discussing before, when you shorten the distance between two ends of a muscle without contracting the muscle it becomes weak. This happens with the diaphragm during slouching. Obviously this changes our ability to breath but it also has an effect on digestion as well. The strength and stability of the diaphragm (the muscle spanning the entire bottom of the ribcage) is important for the smooth transition of food from the esophagus to the stomach as well as preventing herniation of the stomach in to chest cavity during the churning motion of digestion.

We have discussed what happens when joints are improperly aligned so let’s get into what proper alignment is exactly. Proper posture is the position in which joints function best and have the least strain on them. It is easiest to describe this starting at the feet as they act as the foundation for the rest of our body while standing. The balancing point of the feet is the ankles so everything ends up being stacked over them. The knees and hips should be in line over the ankles.

Proper posture of the pelvis is a little harder to explain. When we bend our hips, a crease forms where the leg meets the pelvis. At the outside end of this crease is a little bony bump called the Anterior Superior Iliac Spine (ASIS) and it is the first important reference point in determining pelvic posture. The second reference points are the little dimples on either side of the spine where it meets the pelvis. These are the Posterior Superior Iliac Spines (PSIS). Proper alignment is when these two points form a line that is parallel with the ground. This is hard to determine on yourself but the best way is to place your index finger on the ASIS and try to reach the PSIS with your thumb. Many people may not be able to reach the entire distance but as long as your hand is forming the line between the two points that is enough. Roll your pelvis back and forth and try to level your hand with the ground (or the seat of the chair if you are sitting).

We are going to skip up to the shoulders next. They are much simpler to align properly. The centre of the shoulder joint should be directly in line with the hips, knees, and ankles. This requires that the upper back (Thoracic Spine) be upright and not hunched over as so many of us are in western society. There is no easy way to determine what is too straight or too hunched for this area of the spine so using the shoulders as a guide is the best way. And easy indication of shoulder slouching is to stand in front of a mirror and look at your hands at your sides. In neutral positioning you should only be able to see the thumb pointing forward. In poor posture more and more fingers will be visible from the front as slouching becomes worse and your hands will begin to sit on the fronts of your thighs rather than on the sides of your hips.

Let’s travel back down south for a minute to the low back (Lumbar Spine). There is really no good way to determine the proper positioning of the lumbar spine as every individual has a different “normal” curve. The easiest way to “find neutral” in the low back is by leveling the pelvis and centering the shoulders. With this the low back will align itself without us troubling over it.

The last part of the body to align is the neck and head. This is simple enough to do. For optimal posture the ears should be in line with the shoulders, hips, knees, and ankles. This will align the neck (cervical spine) over the shoulders and thoracic spine and the place the skull squarely over the cervical spine. This will also impact the jaw which is indirectly put under pressure during poor posture.

On top of all this, there is theory that misaligned and altered joints in the spine can alter nerve function as they leave the spine. This changes the balance between the parasympathetic and the sympathetic (rest & digest and the fight or flight) autonomic (involuntary) nervous systems which control the activities of the organs. This theory states that optimal positioning is not only the best orientation for the joint, muscles, and ligaments but for the optimal firing of the nerves and therefore the optimal function of the organs as well. There is no evidence behind this theory that I am aware of but even if this theory is not true, there are still enough other ways that poor posture hurts us that it is important to fix it.

This is a lot of information to process in one sitting I know. So we’re going to leave it here and pick up again next week with some exercises and care for regaining proper posture and relieving the pain bad posture causes.

Thanks for reading,
Dr. Ben

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