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The spine is the body's supporting organ, where the most important tasks of the body take place, mainly thanks to the ductal canal, which is connected to the brain. In addition to posture, it is therefore very important because it also influences the activities of other organs in the body. And what exactly is the spine? The human spine is a bony column that consists of 33 to 34 vertebrae:
It further consists of the coccyx (the sacrum articulately attached to the pelvis, formed by the fusion of the 5 sacral vertebrae (S1-S5) and the rest of the stunted caudal vertebrae, which are fused to the coccyx (Co). The vertebral column is arranged in such a way as to be rigid, but at the same time flexible and bendable. It should enable a person to stand upright and have a large range of movement in space, as it is the axis of all movement of the upper half of the body.
Intervertebral discs affect our height
The function of the spine is ensured by the alternation of the hard bony vertebrae and the parts of the soft ones that connect them to each other. Between the bodies of the individual vertebrae, from the 2nd cervical to the sacrum, there are flexible intervertebral discs. Posteriorly together, most vertebrae communicate through a system of tiny joints. The intervertebral discs consist of a soft and flexible jelly-like nucleus surrounded by a tough ligamentous ring. From the cervical vertebrae to the lumbar vertebrae, the intervertebral discs increase in size as the vertebral bodies increase in size and as the weight load on the vertebrae increases. In aggregate, then, the height of all the intervertebral discs is about 25% of the total height of the spine. A longer load on the spine leads to a slight reduction in their size, which is why a person's height measured in the evening tends to be slightly lower than in the morning. In old age, both the elasticity and the overall height of the discs decreases, thus decreasing a person's overall height. The compressible discs not only allow some slight movement between adjacent vertebrae, but at the same time form elastic buffers which cushion the impact of walking, running, jumping, etc. Significant demands are placed on the intervertebral discs in terms of loading. For example, it has been found experimentally that the pressure inside the intervertebral disc between the first and second lumbar vertebrae is around 25 kg in the supine position, around 175 kg in the seated position and can reach up to 1000 kg under load.
Back muscles and movement
The shape, course and movements of the spine are determined not only by the vertebrae themselves, but above all by the intervertebral ligaments and the massive back muscles, consisting of several layers, running from the back of the head to the coccyx. The whole system of back muscles is divided into three (sometimes 4) groups according to their arrangement. The shortest muscles are located deepest, i.e. closest to the spine, and extend between the vertebrae. They are evolutionarily the oldest, in the past they allowed creeping movement to our ancestors. In the next two layers are longer muscles that span several vertebrae. The longest on the surface are the muscles. In terms of painful conditions, the deep muscle layer is the most important, the innervation of which is provided by the posterior branches of the spinal nerves. Functionally, these muscular systems are the erectors of the spine. Unilateral contraction induces its tilt. The deep short muscles are predominantly static, ensuring a certain position of the spine, while the superficial long muscles are primarily dynamic, participating in the movements of the trunk. The two adjacent vertebrae form a functional segment that is the basic unit of spinal dynamics and can reflexively protect the affected area through contraction of the surrounding short muscles. This local muscle contraction, called spasm, myogelosis or contracture, is also detectable by palpation. Its purpose is to immobilise the affected segment and induce optimal conditions for reparative processes.
Shapes of the spine
When viewed from behind, a healthy spine is straight, not sideways. If such protrusions appear, we talk about scoliosis. Viewed from the side, the normal spine is bent twice in two esses. Curvatures reversed by a backward bend are called kyphosis, curvatures reversed by a forward bend are called lordosis. We recognise cervical and lumbar lordosis and thoracic and sacral kyphosis, the aforementioned curvatures alternating smoothly. Properly developed curvatures are also reflected in the correct shape of the back. If the curves are underdeveloped, a flat back results, which is a sign of muscular weakness. If the head is drooping and the cervical and thoracic spine form a smooth, backward curve, we speak of a round back.
Mobility of the spine
The natural curves mentioned above allow the spine to flex in the vertical direction. They contribute significantly to shock absorption when walking or running. The mobility of the spine is determined by the sum of the small movements between the individual vertebrae, but depends largely on the type of the individual, their lifestyle, physical fitness and age. With increasing age and lack of exercise, the mobility of the spine decreases. Not every part of the spine is equally mobile, the cervical spine and the transition of the thoracic spine in the lumbar spine (THL 1- L2) are the most mobile, the thoracic spine is the least mobile (the sacral region is completely immobile). If you want to keep your spine as flexible and mobile as possible, want to avoid body aches from long periods of sitting and a passive lifestyle, check out the NoPainOffice program. A few minutes a day can save hours at the doctor.
Complexity of the spine and its disorders
The entire spine forms a single functional unit. A mobility impairment in one segment is transmitted to the other segments. Another reason why spinal disturbances can manifest themselves in distant places is the intervertebral foramina, which pass through massive nerve roots, carrying information from the central nervous system to the peripheral organs and vice versa. Thus, cervical spine disorders can also manifest with headaches, dizziness, whistling in the ears, pain spreading through the upper extremities, tingling in the fingers, visual disturbances, upset stomach, and a host of other symptoms. Thoracic spine disorders can also have more distant symptoms such as pain in that area, for example pain behind the breastbone and near the heart. Spinal problems can also cause rib pain and shortness of breath. Lumbar spine disorders may present with, among other things, pain, tingling or a feeling of insecurity in the lower limbs, pain in the groin or small pelvic organs.
