Today’s post is all about levers. Remember those from high school physics? If you had to take physics, you definitely covered mechanical levers. If you didn’t but have ever been on a teeter-totter then you will understand the importance of today’s post.
Upright posture, works just like a child’s teeter-totter (aka seesaw for those in Europe).
If we think of our spinal vertebra, spinal discs and spinal joints (facets) as the fulcrum, you can quickly understand from the above image, that the weight and effort must be the same. If the weight of one child is unequal to the weight of the other child, the teeter-totter is unbalanced and the lever tips gently under the load of the heavier child. If one child is very much heavier, the teeter-totter comes crashing down, due to the extreme load of the much heavier child.
Lets use a common example with posture. If the weight is your head and the effort your neck muscles, and you wanted to exert no muscular effort to hold up your 10 Ib head, your head would need to sit directly over the fulcrum. As the spinal vertebra, discs and joints are considered the fulcrum (your center of gravity), your head needs to sit right on top of your spinal column, or your neck and upper back muscles begin to work overtime, to support the increased load. Let me use a diagram to explain this concept:
Forward Head Posture
In this example you can see your 10 pound head is the ‘weight’, the vertebra is the fulcrum and the muscle contraction is the ‘effort’ needed to support your head. Notice the head is 3″ too far forward – we call this Forward Head Posture or FHP. In physics we work out the ‘effort’ required by multiplying the weight (10 Ib head) by the ‘lever arm’ (the distance from the fulcrum – 3″ in this case). That’s all the math; I promise! So when you have just 3″ of FHP, your muscles require 30 Ibs of extra effort to maintain your head in this forward position.
NOW, DO YOU NOW UNDERSTAND WHY YOUR SHOULDERS ACHE?
If the above example, your fulcrum is once again, your spinal column; the ‘weight’ is the extra abdominal fat and the ‘effort’ is the muscles in your lower back (the erector spinae muscles). If you are lean, then your center of gravity is directly in line with your fulcrum and your body is balanced requiring minimal muscular effort. As your body weight increases, so does the constant muscular effort. Are you starting to understand why your lower back is always aching?
If you have a long history of one-sided lower back pain, you may have an anatomical short leg (as I do) and you may just benefit from a Posture Analysis. In the above example, the fulcrum is your sacrum (the triangular bone to which your spine anchors); the ‘weight’ is your leaning body caused by a left-sided short leg and the ‘effort’ is the muscular contraction of the quadratus lumborum muscle (known as the QL). This is a very common source of one-sided lower back pain.
So the moral of this posture story? Upright posture is a first class mechanical lever – to use mechanic’s speak. Postural distortions like forward head posture, being over-weight or having an anatomical short leg lead to chronic muscular contraction, which leads to tissue ischemia (cut off blood supply), inflammation, fibrosis (think scar tissue) and disability – reduced range of motion, inflexibility, chronic pain and eventual wear and tear – aka osteoarthritis.
These are only the physical effects. There are neurological effects of postural distortions that effect your organs but this story I’ll save for another day, another post. So a pretty frank beginning to my posture blog but I want you to get that poor posture is so much more than how you sit and stand. The effects are very real. You can’t afford to ignore your poor posture for even just one more day. Fear not, I am here to help you.
So until next time, remember to fidget, wiggle and stir!