Neurology Medicine

As has been demonstrated that back pain is not always due to an organic disorder of the spine, have begun to study the factors associated with an increased risk of autism. We must be cautious in interpreting these studies show that back pain sufferers have some characteristics more often than non-sufferers. That means that these factors are associated with an increased risk, not necessarily to be the only cause of pain or that their removal improve it.

Despite this limitation, in those cases where you have to take into account factors rigorous epidemiological studies show that are associated with an increased risk of back pain, especially in cases in which the mechanism can be glimpsed explain their potential influence. Some of the factors that have been most studied are:

- Flexo-repetitive extension of the spine, is associated with increased risk of back pain.

On flexing the spine causes increased pressure inside the intervertebral disc. If at that time weight bearing and re-straighten the spine, the pressure in the back of the disc which can increase both cracked or broke, causing a herniated disc. This process can occur once, if the effort is intense, but usually occurs by a mechanism of accumulation: each improper bending increases the impact of the nucleus in the fibrous disk and erodes until crack or break.

In addition to the disk, also the muscle is overloaded to keep leaning forward. That position is possible thanks essentially to maintain controlled tension of the paravertebral muscles, gluteal and hamstring, which prevents the body from falling forward. The larger the bending angle, the greater the effort required to perform the lumbar musculature and the lower the number of segments that do, making it easier to overload.

Mechanistic studies show that disc and muscle overload is greater if the inclination is done with straight legs, and lower when flexed knees and keeping your back straight.

In fact, epidemiological studies have shown that back pain is most common among those who perform repetitive motions of flexion and extension of the spine, especially if they handle cargo, if it is excessive or if your muscles are inadequate.

- Torque or frequent rotation of the spine is associated with increased risk of back pain. From the shape of the vertebrae, the cervical spine can rotate more than the back, and this more than the back. Probably exaggerated repetition of rotations in the lumbar spine can overload the facet joint and muscles, and even also the disk, especially if it is bearing weight.

In fact, epidemiological studies have shown that back pain is more frequent among those who perform repetitive motions of twisting or rotation of the spine, especially if they are driving charge, if it is excessive or if your muscles are inadequate.

- Efforts; are associated with increased risk of back pain. This association may be due to an overload mechanism, and may be associated with an increased risk if efforts are made in positions of flexion and extension or rotation:

An intense effort can cause back pain. If the muscles are very powerful, is injured before the intervertebral disc. In this case the pain caused by muscle injury, painful but benign and usually resolves itself in a few days, avoiding the effort to maintain and protect the intervertebral disc. If the muscle is not strong enough, the intervertebral disc may be injured while the muscles.

It is possible that the continuous repetition of efforts, though not terribly severe, can cause back pain probably due to the accumulation of small lesions in the intervertebral disc, facet joint or, more commonly, repeated overloading of the musculature.

Excessive strain does not always mean load weight: the adoption of awkward postures can overload the muscles or the structures of the spine. If the positions remain inadequate enough time or frequently recurring back pain can cause an overload mechanism is loaded but not weight.

It is true that a particularly intense exertion and carried out without taking into account the postural hygiene, especially if it occurs in a movement of flexion and extension, can trigger a painful episode. However, this process typically does not make it normal. Most commonly, back pain episodes occur without the effort has caused.

Epidemiological studies show that back pain is more frequent among those who perform repeated intense efforts, especially if they are in positions of bending, twisting or rotation of the spine, or in cases where the muscle is insufficient.

- Vibration; is associated with increased risk of back pain. Epidemiological studies show that the vibration affecting the whole body increases the risk of back pain appear. That is the case, for example, tractors and machinery to handle this type. Vibration is likely to trigger the pain of these mechanisms:

Vibration entails rapid shortening and lengthening the muscles, which could facilitate its contracture.

The vibration increases rapidly cyclic load on the intervertebral disc and facet joint.

The vibration causes direct activation of pain nerves in the spinal ganglia.

- Lack of power, resistance training or back muscles, is associated with an increased risk of back pain and that pain will recur or become chronic. Studies have confirmed that back pain comes on more easily and persists longer in people who do not have a sufficiently powerful muscles, strong and trained. Probably, this fact is explained by several mechanisms:

If the muscles are strong and harmonious, the load distribution is correct and decreases the risk of contractures or muscle overload.

The greater the power and muscular endurance, the greater the structural strength to the load.

Normally, the muscles begin to ache before the other structures of the back, so that warning of possible injury. If the muscle is very powerful, this mechanism does not work effectively.

Normally, the muscles reports the position in space. When the muscle is poorly trained that source of information is faulty, so adopting bad posture without being conscious of it.

- Feeling discomfort in bed is associated with an increased risk of back pain. Studies show that back pain is more frequent among those who feel discomfort when lying in bed or on rising.

In some studies, discomfort in bed has been associated with a risk of up to 1800% more back pain, both among adolescents as among adults, while most of the other factors studied (such as gender or physical effort at work or leisure) have been associated with much less effect. In addition, scientific studies have also shown that among people who already suffer from back pain, mattress firmness influences its evolution, so a medium firm mattress is recommended that one very strong. These data suggest that the surface characteristics of rest are a relevant factor in relation to the existence or development of back pain.

It is possible that this influence is due to several factors. If the characteristics of bed induce the adoption of poor posture while lying down, you can alter the burden-sharing in that position, affecting the muscles (by inducing its overhead or simply hinder their relaxation) or increasing the burden on intervertebral discs and facet joint. Since this factor would act repeated and prolonged (estimated a subject spends approximately one third of your life in bed), medium or long term inadequate sleep in a bed could induce alterations in the structures.

- Have experienced previous episodes of back pain is associated with an increased risk of back pain. Scientific studies show that once a patient has had an episode of back pain, is likely to return to have others in the future. Some of the recommendations based on scientific evidence establishing that the majority of patients are repeated painful crises from time to time, without necessarily meaning that they are getting worse or that they have become a back injury. This could be explained by several reasons:

Those with a crisis often have one or several risk factors related to their lifestyle or characteristics. Unless special measures are taken, which is not always easy-change of habits, exercise etc .- is likely that these risk factors continue to rise to new episodes.

Studies show that back pain causes muscle contraction by a neurological mechanism, and the muscle receives less blood flow while contracture. This may facilitate re-contracture in the future and provoke new crises of pain, especially if kept idle during the painful episode or from him. On the contrary, maintain the highest physical activity level as possible (when there is pain as well when it is not), improves risk and status of the muscles, reducing the risk of the occurrence of back pain and improving its development when already have.

Studies also show that if the back pain limits activity for some time the muscles will atrophy easily. Atrophy of muscles can make more vulnerable the column and make it difficult to adopt the correct postures, which in turn may increase the risk of new episodes of pain.

A neurological mechanism explains that if the cells perceive pain in the spinal and brain remain active for some time, increases the ease with which they are activated in the future, so that small stimuli can cause back pain. In fact, if their activation lasts long enough, tend to stay activated even disappears painful stimulus that initially triggered, in which case the pain persists even though their initial cause disappears.

- The attitude to pain, influence the risk of pain and especially in its duration and the risk of recurrence. The available studies show that patients who have suffered back pain can react in two ways:

- A (the “elusive”) is frightened by the pain and fear for their future, mistakenly thinking that every time they notice a sore back necessarily mean that the injury is getting worse. So rest a lot, avoid physical activity, waiting passively for the pain better, and tend to abuse drugs, especially painkillers.

- Others (the “combative”) does not fear for their future and hope the pain will get better or if not, can adapt to it. They have a life as normal as they can, keep active and go to work, avoiding only what really prevents them from pain and not afraid if you ever notice an annoyance.

The available studies show that, in connection with the “elusive”, the “militant” are less likely to suffer back pains back and, if present, they take less.

These facts are explained by several reasons:

- First, by psychological aspects: the “elusive” tend to obsess about their pain and discomfort interpret the passengers who may feel at any given time reflect a serious injury. Therefore, it is stressed, which is an additional risk to your back. In addition, anxious and depressed more easily, making that tend to further magnify the pain they feel.

- Apart from the physical point of view, excessive rest and inactivity tend to accelerate loss of muscle strength and endurance, making the back more vulnerable to overload and facilitating the risk of recurrence or pain perpetuation .

- Stress, increases the risk of back pain. It really has more influence on the perception of pain in the risk of appearing, ie only increase the likelihood of a sore back, stress makes it be perceived as more intense pain. Probably there is a dual mechanism:

Stress can alter, increasing the perception of pain.

Some data suggest that stress can cause increased muscle tone and facilitate the development of contractures, although the studies that have compared the electrical activity of muscle of stressed and unstressed patients have provided conflicting results.

- Dissatisfaction, increases the risk of back pain, and especially the episodes that last longer. Studies in the workplace reflect dissatisfaction with the job increases the risk of back pain and increases the period of leave. From the medical point of view, and outside employment considerations, the mechanism that can explain their influence may be twofold:

A mechanism similar to the stress.

Somatization unaware of the dissatisfaction with life in the form of back pain.

- Some types of personality, affect the risk of the occurrence of pain and, above all, the risk of becoming chronic and the restriction of the activities involved. Some studies suggest the existence of their own psychological characteristics of patients with chronic back pain, than those of patients with other chronic conditions. These personality types can facilitate the obsession with somatization or back pain, which reaches into the heart of the patient’s life. Although the research methods used in some studies not possible to determine whether these abnormalities are cause or consequence of chronic pain, others suggest that certain personality types may facilitate the perpetuation of pain.

- Smoking; their effect is dubious. Although earlier studies coincided in pointing out that back pain is more common among smokers than among nonsmokers, long questioned the influence of snuff because they do not know the mechanism that might explain it. Attributed to smokers usually do physical work more often, because they generally belong to a sociocultural level lower than nonsmokers. However, scientific studies have shown that the deleterious effect of snuff on the risk of back pain is maintained regardless of the sociocultural level, and their influence attempts to explain:

The irrigation of the intervertebral disc. Now normally in a healthy individual, the nucleus pulposus is irrigated and non-fibrous receives less blood. In the smoker, traffic is worse and could deteriorate further irrigation of the fibrous and could accelerate degeneration or facilitate injury.

Cough. The smoker often cough more than non-smokers. Coughing raises the pressure in the intervertebral disc and subjected to vibration, which increases their risk of degeneration or injury.

The musculature. Smokers tend to be in worse physical shape and have less muscle and worse than non-smokers, which could facilitate the overloading of the spinal structures and the occurrence of back pain.

However, some studies have concluded that there is no clear dose-dependent relationship of snuff. That could suggest that snuff behaves as a “confounding variable” (ie, has no effect in itself but acts as an indicator to be associated with other factors that are really increase the risk of suffering pain back), or the adverse effect of snuff on the back manifests from very low doses, without significantly increasing effect with increasing dose. In any case, there are many health reasons for not smoking, whether or not its association with back pain.

- Overweight, his influence is questionable. For years it was believed that overweight representing an increase of the load on the spine and thereby increasing the risk of back pain. However, when studies have been done to see if it really were so, conflicting results were obtained. Although some research suggests that overweight may slightly increase the risk of back pain, most rigorous studies show that, contrary to what was previously believed, its effect is not so relevant. In short, now you can not say with certainty qu overweight increases the risk of back pain, and it was found that if he really has an influence, it is minimal. However, studies show that reducing excess weight improves health in regard to other conditions such as cardiovascular or endocrinological and therefore worthwhile to control although its effect on back problems is at most doubtful.

- High stature, its influence is questionable. For years it was thought that, other things being equal, the back pain was more common among those who were higher due to increased load that the height involved. However, epidemiological studies do not confirm this assumption. It is arguable that the size increases the risk of back pain and, if so, their influence is minimal.

- Sedentary lifestyle, their effect is dubious. For many years it was thought that the fact of sitting for prolonged periods in itself increased the risk of back pain.

There have been very few studies to evaluate the effect of the characteristics of the chairs on the risk of pain or its evolution, and research methods used prevented with certainty that these characteristics have a decisive effect. However, some studies suggest that school with furniture characteristics influence the risk of the occurrence of back pain and its medium-term development. Thus, evidence suggests the convenience of using chairs adaptable, allowing adoption of correct postures when they must be maintained.

However, regardless of whether it is convenient to use chairs to permit the adoption of the postural hygiene, studies consistently demonstrate not that the number of hours they spend sitting in itself means a risk of suffering pain back. Today it is believed that adults rather than the fact of sitting in itself, which is harmful is the lack of physical activity than usual enter the sedentary. Thus, this factor influenciaa eventual attempts to explain by a double mechanism:

Maintenance prolonged sitting posture involves the loss of abdominal muscle strength and paravertebral, so there may be small-overload-strain or positions that cause pain.

Maintaining this posture, especially when not taken properly, greatly increases the pressure in the intervertebral disc, which facilitates its degeneration or injury, or is likely overloading the muscles.

Moreover, and although there is scientific studies, patients with back pain that often are worsened by weather changes. One explanation might be the variation of atmospheric pressure. Both within the intervertebral discs (especially if they are degenerate) and in the joints, including the facet joint, is empty (zero pressure). This vacuum makes the bones are kept together. The decrease in atmospheric pressure could cause a suction effect that eventually exacerbate existing inflammation in the area. That would explain the pain to appear or to worsen with decreasing atmospheric pressure, ie a few hours before it changed over time.