Natural selection acts solely by accumulating slight successive favourable variations, it can produce no great or sudden modification; it can act only by very short steps. - Charles Darwin Structure governs functionDuring my time at university, I was introduced to the principle "structure governs function". In anatomical terms, this means that our bodies developed in a way that serves a specific, necessary ability e.g. 4 fingers and a thumb which allow humans to grip, use tools and illustrate hand signals as communication. I use the word necessary intentionally. Darwin's theory of evolution by natural selection tells us the long term changes to anatomy and physiology only occur when they give an organism an advantage, therefore being deemed necessary. There was always debate amongst my peers and lecturers on whether this principle can be flipped around; "function governs structure". In the short term, yes. When a person permanently loses a sense, for instance hearing, it's common knowledge that the remaining senses often become heightened. A study published in the Journal of neuroscience in 2012 found that when the brains of congenitally deaf people were observed through fMRI (A fancy MRI scanner that allows activity of the brain to be monitored), the researchers found that rather than the area of the brain that is in charge of hearing (Heschl's gyrus) being missing or empty, it's role had been altered through the process of neuroplasticity to detect vision and touch. However, this trait is not passed on through reproduction and the function of the parents advantageous vision and touch has not altered the structure of their child's Heschl's gyrus. The reason for this is summarised in the Darwin quote at the top of this page. Permanent changes to anatomy only occur over extremely long periods of time, in tiny incremental progressions. Therefore, it doesn't appear that function can govern structure, particularly in the short term in a way that will positively adapt a human being to a new day to day lifestyle. This, I believe is the underlying issue of modern societies battle with pain, stiffness and disease. It gives a reason as to why our bodies don't suddenly alter themselves to suit our office jobs, evenings slumped on the sofa, diets dense in processed foods and the 3-4 hours UK adults spend on average watching television every day. The industrial revolution1760 announced a new era of industry, jobs and daily life in Britain and America. Before this period, goods and commodities were sourced and developed by hand. Daily life would have looked quite different to that of today. Calculations made by 'Teaching with themes' estimated than pre industrial women would have burned on average 2525 cals, compared to todays 1704 cals. The movements performed to use this amount of energy were also likely to be more diverse in nature. Rather than pulling levers or lifting uniformed size boxes on a conveyor line, or sitting at a desk on a computer for 8 hours a day, people would have worked in a variety of roles at once in order to produce goods and serve society. When returning home from hunting or gathering, pre industrial man would have had no option to sit and watch TV. They would likely have adopted a variety of different sitting or resting positions, utilising their muscles and joints in ways that in the 21st century, can only still be observed naturally in non western societies e.g. India where squatting is common, or tribal settings. Mainstream thinking suggests that it took around 2 million years for the first human like species like homo erectus to eventually evolve into todays homo sapiens. It then took another 50,000 years for homo sapiens to develop a language that could be used in large colonies. This example highlights the importance of time and gradual changes through natural selection. Going back to the industrial revolution which begun 260 years ago, it's clear humans still have a way to go before they adapt to todays machines, desks, TV screens, bar stools, car seats and meals out. Early homo sapiens would have travelled vast distances, hunted food in groups, spent time daily nurturing crops, building or rebuilding shelter, defending themselves from other homo sapiens and predators, carrying babies everywhere they went and sleeping on firm surfaces with make shift cushioning underneath. At West-Gate, it's often assumed amongst patients that those with arduous manual jobs e.g. farmers, builders etc would present the most to clinic with some sort of pain, injury or discomfort. Although these professions result in plenty of injuries and overuse issues due to repetitive heavy movements, it's often the desk worker that suffers more. Interestingly, even the farmers report that their worst time of year is when tractoring or combining increases. They're essentially sat in a seat all day looking over their shoulder. So what is it about desk work that aggravates the human body. Really, it's a three pronged attack. The first of these spikes being positioning or posture. In a seat, the bodies postural muscles such as erector spinae, glutes, hamstrings, abdominals, anterior neck muscles) are all places in positions where they either relax for long periods of time, or are over worked without the relief of movement. This results in us essentially slumping against our own skeletons. Low back and neck pain is particularly common as we depend on the deep integral ligaments and the intervertebral discs of the spine to keep us upright. There's a reason sciatica is so well known, the sciatic nerve route simply corresponds with the two most weightbearing joints of the low back. L5 and S1. The curves of the low back are also compromised. Stand up and observe how you or a partners natural spinal curves help you stand. Usual for a person, is a lordotic or 'inward' curve of the neck and low back, whilst the opposite is true for the thoracic spine which should curve 'outward' in a kyphosis. These curves play a large role in shock absorption and movement. Now observe your postures when sat at a desk. Unless you have an expensive chair or cushions, it's likely your low back will slump into a kyphotic position, the thoracic spine will be forced to become ever further leant forward and the neck or cervical spine will have to fight against both of them to extend itself to allow the face to point forward. When looking down or reading, the neck drops further into its new kyphotic position, causing the entire spine to be placed in a large slumped curve, crunching the abdominal muscles and forcing the back muscles into a stretched but constant strain. The second prong is what you could describe as muscular imbalance or muscle compensation patterns. This process causes large muscle groups to be held in opposing positions. The hamstring are shortened when sitting at a desk, whilst their antagonist partner the quadriceps is lengthened and tethered over the bend at the knee. Muscle groups also differ in use and tone for long periods of time as seen in the neck. The large powerful trapezius muscles team up with the intricate multifunctional levator scapula muscle, leading from the medial corner of the scapula up to the neck. These two muscles work hard allowing the head to remain facing forward whilst angled downward toward our laptop or mobile phones. The opposite is true for the muscles of the anterior neck, The large sternocleidomastoid muscle which originates at the sternum and latches itself onto the mastoid process behind the ear is underworked, having to occasionally spring into action when a colleague calls our attention from across the room. The effects of sitting culminate in the third prong. Sedentariness. Keeping the body still for long periods of time causes many problems through a variety of bodily systems. The large calf muscles of the lower leg can no longer assist venous return of deoxygenated blood back to the heart and lungs, resulting in swelling or pooling of the lower limb. Lack of exercise and energy expenditure results in the long term process of atherosclerosis or the laying down of plaque deposits in the cardiovascular system that over time can lead to heart attack and stroke. The weight increase accumulated over years of desk work contributes to the strain put on the weightbearing joints of the body, hips, knees, ankles. Resulting in arthritis and early joint replacements. The respiratory system is also affected. When the spinal curves are compromised as discussed in the aforementioned paragraph, the diaphragm has less space to elevate and depress, the ribs are brought closer together resulting in a tightness through the intercostal muscles. The lungs which require adequate space in the thorax are compressed which results in shallower breaths. What can be done to counteractive an inescapable world of sedentary jobs and stationary hobbies.Be more caveman. Here we will go through just a few ways you can counteract the damage caused by the factors above. They will hopefully be fun, productive and lead individuals to feeling less stiff and achy, less susceptible to injury. The dopamine hit we gain from activity should also leave us feeling happy and accomplished too. 1- Primitive postures. I came across this concept whilst working with sports osteopath Aaron Casely at the Mofo (Minority of one) clinic in Leeds. We set patients the challenge of choosing two or three primitive postures to adopt whilst continuing with their usual chilled out evening. These could include lying on their front, sitting against a wall with legs outstretched or sitting in a squat or lunge position. These postures should be alternated every so often to avoid the same issue of being in the same position for too long. Remember, positions, even at the desk only cause an issue when they're adopted for too long a period of time. 2- Think about what movements or positions you have to do the most through out the day. This includes if you're an athlete. Then find an activity which requires a completely different plane of motion. Here's two very different examples. The patient is a competitive golfer, they spend hours a day walking and continuously swing the club the same way. A good exercise for them, would perhaps be to perform a spinal rotation exercise to the other direction, like a banded or cable wood chopper, or thread the needle. A desk based worker would benefit from yoga, so as the gain all the movements they lack during the day as well as spinal extension to counteract the flexion at the desk. 3- Pick a new lifestyle activity that would replicate the way a human would have been required to move thousands of years ago. A great example of this is jiu-jitsu. Grappling, wrestling, high heart rate, difficult positions, vulnerability and competitiveness. What could be more natural. As you develop through a sport like this, your body will develop too. You'll use muscles you've not developed to a functional level before, and natural movements like shrimping, rolling, squatting and lifting will become comfortable. 4- Cushions and mattresses. The osteopaths and sports therapists at West-Gate always instruct patients to ensure that when they're sat for long periods of time, they have a lumbar support, small cushion or rolled up towel placed in the curve of the lower back. Starting from the bottom is the most important thing. This will allow for natural spinal curvature to continue up the thoracic and cervical spine. Another common issue of todays society is our loves of soft cosy mattresses. Although these may feel lush when we first get in, they don't offer much support to the body. Again, reflect back to the firm forest, cave and grassy floors humans learned to sleep on. There would have been some sort of cushioning to avoid aggravating bony areas like hips and knees, but the general structure of their make shift beds would have been extremely firm and unyielding. 5- Manual therapy and movement. Our practitioners offer the best hands on treatment available, with a range of techniques including; soft tissue massage, joint articulation, mobilisation, manipulation, stretching, taping and more. These sessions are usually always paired with exercise prescription as there really is never any substitute for movement. Movement is therapy in itself. If you work at a desk or in a manual job, or just generally feel stiff and achy. Consider booking yourself in with your local osteopath, sports therapist or physiotherapist. You don't need to have a painful acute injury to present at clinic. As well as hands on treatment and exercises. Osteopaths give valuable lifestyle advice for you to make confident, sustainable changes to help your health. References1- Christina M. Karns, Mark W. Dow and Helen J. Neville. (2012). Altered Cross-Modal Processing in the Primary Auditory Cortex of Congenitally Deaf Adults: A Visual-Somatosensory fMRI S. Journal of neuroscience. 28(32), pp.9626-9638. [Online]. Available at: https://www.jneurosci.org/content/32/28/9626.abstract?sid=554f9c9c-ec7e-4c33-87a0-3f2416e52e24 [Accessed 12 January 2023].
2- Catherine Hiley. (2022). Screen time report 2022. [Online]. uswitch. Last Updated: 2022. Available at: https://www.uswitch.com/mobiles/screentime-report/ [Accessed 12 January 2023]. 3- Teaching with themes. (-). Comparing modern nutrition and exercise to the pre-industrial era. [Online]. Teaching with Themes social history through primary sources. Last Updated: -. Available at: https://teachingwiththemes.com/index.php/projects/comparing-modern-diet-exercise-pre-industrial-era/ [Accessed 17 January 2023].
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