Why a Mutant Fish is Responsible for Your Sore Back
If you asked an inventor or an overpaid corporate engineer to design a gadget, the first thing that they would want to know is what it was supposed to do. No sensible person would design an object and then assign it a use when they had finished. Usually, the design of something depends upon its purpose. Function dictates structure.
Your spine is no different. Its myriad of strange shapes and complex joints serve very worthwhile purposes. Those funny little pointy bits on the bones did not appear by accident. If you understand the function of your back, and how those demands evolved, then you will find it far easier to appreciate its bizarre structure. Later, armed with this knowledge, you can confidently tackle tasks such as diagnosing and preventing your own back pain.
The Evolution of your Spine
Mother Nature designed your spinal column over a very long period. Helped by her design team of natural selection and evolution, she gradually fashioned the extremely complex systems that form the human spine.
The process began about half a billion years ago when an otherwise inconspicuous ocean-dwelling animal called an Elasmobranch developed a spine. The Elasmobranch’s spine was a flimsy affair: its chief function was to provide protection for the bundle of nerve fibres that ran down the creature’s back. Despite this inauspicious beginning, the vertebral column had arrived.
Over the next lazy 100 million years or so, other sea life such as primitive fish slowly evolved spines. These spines were also very simple, and made from soft cartilage rather than bone. They gradually assumed another job besides protecting the nerves: to provide an attachment for the fish’s muscles. This extra control allowed them to swim, and thus survive, more efficiently.
Then, about 400 million years ago, the fish did something that had a huge effect on our spinal development: they migrated to land. With this audacious move came a new problem for the spine. Gravity.
Helped along by the very small changes that are evident from one generation to the next, these early amphibians gradually developed newer, different models of the spine. The quality control manager, natural selection, tested each new design. Those animals with more efficient spines had a better survival rate, meaning that their descendants, the reptiles, inherited better backs.
By the time mammals arrived about 250 million years ago, the vertebral column had developed many desirable characteristics:
- The individual building blocks of the spine were now constructed from dense bone rather than cartilage. This change allowed them to bear more weight.
- The vertebrae—the back bones—developed joint structures that allowed extra movement.
- Shock-absorbing mechanisms evolved that helped to protect the bones from fracturing in the rough-and-tumble of prehistoric Earth.
- Strange lumps and bumps of bone developed on the vertebrae. These protuberances provided leverage for muscle attachments, allowing more precise movement control.
For a time, everything went smoothly in Mother Nature’s spinal design department. She had an efficient, working model that allowed good movement, offered a firm attachment point for both muscles and ribs, while offering vital protection to essential nerve structures.
Then about fifteen million years ago, probably on an otherwise ordinary Tuesday or Wednesday afternoon, all that contentment dramatically changed. Something happened that would alter the requirements of the spine, and therefore its structure, forever: an apelike creature began to walk on two legs.
Why did the ape do this? Well, nobody knows for sure. However, scientists and anthropologists suspect that the motivation was so that the creature could use its front legs—its arms—for tasks such as using crude tools, or brandishing weapons for self-defence. The two-legged stance also liberated the front legs for the useful purpose of carrying objects, like food. Or beer cans.
Mother Nature and her design team now had to enable the spine to cope with a new functional requirement: to support the trunk in the upright position. Suddenly, the architecture of the lower back needed a drastic overhaul. Undoubtedly, the first versions were poor. Any decent spinal health practitioner would have made a fortune had they been around during these early reformative millennia. However, as the centuries ticked by, evolution again provided gradual improvements. The pelvis and hips gradually changed their alignment so that the legs were roughly in line with the trunk, rather than jutting out at right angles like a quadruped’s limbs. The abdominal muscles also changed their function so that they supported the spine in an upright position, rather than simply being a sling for the stomach and intestines.
As we developed, tree climbing became an occasional diversion rather than a semi-permanent home. Our tails, which were no longer necessary, steadily disappeared … which I, for one, think is a bit of a shame. Imagine how much fun you could have at a party with a fully functioning tail.
Recently, only a mere two or three million years ago, we human beings emerged from the developing gene pool. We now walked upright most of the time. In response, the spine made one further adaptation: it developed some inward and outward curves. Besides providing some extra leverage for the postural muscles, the curves had a springlike effect that helped the spine to absorb shock.
Finally, after a 500 million year journey that started with a mutant fish, the spine arrived at the current model.
Despite the miracle of design, I award Mother Nature only nine out of ten for her efforts in spinal architecture. Why the deducted mark?
The lower back is probably the weakest mechanical link in the entire human body. It is responsible for more musculoskeletal pain than any other area. Compared with other masterpieces like the eye, the brain and the hand, the lower back looks decidedly amateurish. Paradoxically, the probable reason for this weakness also lies in the mechanism of evolution.
In our earliest caveman days, health problems of all kinds beset the average human being. Even a simple cut or abrasion was often fatal, while the most common form of death was infection from tooth decay! Because of these appalling health problems, most human beings died at a very young age, usually less than thirty. Of course, most reproduction and parenting had to be completed by the early twenties to squeeze into this limited lifespan. Due to the early parenting age, the natural selection process had no chance to attack the residual problems in the lower part of the spine. Most people had already produced their offspring and/or were dead before they had even begun to develop a bad back, which, as we will see later, usually occurs first in early middle age.
So we passed this weak genetic link from one generation to the next, while it patiently waited to make its presence felt when the human lifespan elongated. Now, as the average length of life approaches eighty years, we are, as a race, suffering from far more back pain than our early ancestors could have imagined.
Yet for all its problems, our spine is an amazing and complex piece of machinery. Try to envisage any other design that not only protects the nerves that carry signals from the brain to the limbs, but provides efficient attachment for both ribs and muscles. Of course, this design would also have to allow plenty of movement without being unstable or floppy, protect itself with shock absorption, and stay upright while being supported on only two legs.
The spine, despite its faults, is really very clever. We’ve got that mutant fish to thank!
This article is extracted from “Back pain: How to get rid of it Forever: Volume 1 – The Causes” by John Perrier. The e-book is available to download for FREE at amazon.com, along with it’s companion “Volume 2 – The Cures“. For a complete list of retailers of both the paperback and e-book versions please see www.JPpublishingAUSTRALIA.com .
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