What is ergonomics?
Ergonomics is a relatively new concept. The term "ergonomics" was first used by Professor Wojciech Jastrzębowski in 1857, in the magazine "Nature and Industry", in his article "Ergonomics in a sketch, or theory of work based on laws derived from Nature". Studies on ergonomics were resumed as late as the 1960s, while in Poland the science was re-discovered in the late 1970s and early 1980s, and since that time it has imperceptibly
forced its way into our homes and workplaces.
forced its way into our homes and workplaces.
Ergonomics has been defined in a number of ways. According to the Online version of the PWN encyclopaedia, ergonomics is derived from the Greek words érgon (work) and nómos (law). It is a field of study devoted to the analysis of the rules and methods required to adapt working conditions to meet the physical and mental features of human beings, in accordance with the requirements proper to physiology and work psychology so as to protect life and health as well as to promote the best personality development possible. In other words, it is the optimum adjustment of equipment, devices and interiors to suit our physical predispositions and social needs.
These days, ergonomics is applied in nearly every field focused on manufacturing convenience goods and with regard to working environments and conditions. As early as the Second World War, designers started paying attention to adjusting aircraft and other combat machinery to suit the capabilities of the average combatant. Currently, when taking advantage of the discoveries in the field of ergonomics, emphasis is being put on designing work places.
Ergonomics is a multidisciplinary science, because it combines three groups of exact sciences: humanities, work organisation and technology. At the moment, we differentiate between two approaches to ergonomics: conceptual and corrective. The former intends to introduce ergonomic principles while developing concepts and designing devices or interiors. On the other hand, corrective ergonomics focuses on adjusting current work stations or devices to ergonomic-specific requirements.
Spine on the turn
Problems with the spine are part of the group of civilisation-related diseases. Over the past few years I have noticed a significant decrease in the age at which the first problems with the spine appear - there are now increasing numbers of patients who are still in their early thirties. Back pains are very serious and they often lead to absenteeism at work or prolonged sick leaves. Treating spinal conditions is difficult and does not bring positive results because of the frequent recurrence of the disease. We wonder why this is so and how can we deal with this situation? We contribute to back pain ourselves, while the fitness of our spine depends to a great extent on our behaviour. We can compare ourselves to cars - the greater the mileage, the greater the wear. Correct use is what really matters!
Evolution has perfectly adapted our bodies to move in an upright position. From the point of view of biomechanics, the spine is an ideal structure. Our problems begin with the progress of civilisation, in short, in terms of lifestyle; we have stayed ahead of evolution. We have evolved from upright beings into the sitting ones. Chinese medicine assumes that the correct functioning of the muscular and skeletal systems can be ensured thanks to everyday physical activity equivalent to continuous walking for eight kilometres. In the majority of cases, our level of activity is far from this standard. The structure of the spine is adapted to movement rather than sitting or standing still. However, to understand what is harmful to us, we need to know how the spine itself works.
A complex structure
From the point of view of biomechanics, we can differentiate between the anterior and posterior spinal column. The anterior column is responsible mainly for carrying loads and it is composed of vertebral bodies and intervertebral discs. The posterior column is responsible for movements and controlling them; it is composed of zygapophyseal joints. In terms of carrying loads, the crucial role is played by the intervertebral fibrocartilage known as the disc. The disc is 80% water, while the rest is constituted of proteoglycans and collagen. It has a very low blood supply and metabolism. Problems with providing nutrients to the disc appear after reaching the age of thirty, when the arterioles supplying blood from the vertebral body are affected by obliteration. Further nourishment is possible only by way of diffusion. When pressed, the disc becomes dehydrated; waste molecules are removed to the bodies of the vertebra surrounding it. When the pressure is relieved, the process is reversed; the disc draws water and nutrients (oxygen, glucose) in from the vertebral bodies. In effect, the disc works like a squeezed sponge.
Changes in the level of disc hydration are the only means of transport for nutrients and metabolites. For the disc to function properly, it is extremely important that these changes are cyclical and take place under the right pressure. Too monotonous pressure, typical of prolonged periods of sitting, lead to disc dehydration, slower metabolism and degeneration. A dehydrated disc becomes more prone to mechanical damage. As a result of excessive disc compression, by the end of the day the spine will be shorter by about 2 cm, causing the loosening of ligament system and increased instability. This situation is one potential source of pain. Shortening of the disc reduces the surface of the intervertebral foramen, which exerts pressure on the nerves and other vessels in that area. This leads to changes in the distribution of loads, which are moved from the vertebral bodies to the intervertebral joints, which, in turn, leads to their degeneration, inflammation and pain.
In a sitting position
The recommended prevention method includes the avoidance of prolonged periods spent sitting, but this proves impossible for many professions. The best position favouring the regeneration of the disc is a lying position, which reduces overload and the resorption of extracted water. However, since this is impossible for many activities, another solution would be a modern mechanism that minimises excessive pressure, offered by ergonomic Profim chairs. It adjusts the angle of the backrest, modifying the position easily and varying the pressure on the disc. Different compression levels lead to changes in disc hydration, which favours nutrition. This is the only device which solves the problem related to working in front of a computer. Using laptops with integrated keyboards and screens lead to the incorrect position of the head while working, and since the head is constantly leaned it causes excessive pressure on the suboccipital muscles. This is one reason for increased tension, compression on the discs, fatigue and a number of conditions (including neck pain, headache, pain in the interscapular region, etc.). Profim offers an active headrest, whose adjustment allows the head to be positioned in a relieving position.