Flat back

Fixed flattening of the lumbar lordosis and lumbar kyphosis ("board symptom", "flat back") is one of the striking manifestations of lumbar osteochondrosis, this symptom attracted relatively little attention of some authors, while others did not pass by another deformation - scoliosis. This is explained, apparently, by the great strikingness of the latter deformation, as well as by the fact that scoliosis to a greater extent and more easily than kyphosis was logically associated with one-sided "sciatica", "radiculitis". When the vertebrogenic nature of the disease was established, vertebrogenic syndrome and, in particular, flattening of the lordosis became the object of attention of all clinicians.

The severity of the symptom of smoothing of lordosis or kyphosis was previously associated with the "expediency" of this installation. Extension of the lumbar spine in the presence of a disc herniation leads to increased pressure on the posterior sections of the fibrous ring and the posterior longitudinal ligament, and often on the root. In the presence of a disc herniation, the indicated irritations of the fibrous ring, posterior longitudinal ligament or root are possible already in the normal position of the lumbar region - with normal lordosis. A decrease in this lordosis, and especially the formation of kyphosis, in such conditions is a protective posture. With regard to the cervical level, the possibility of kyphosis is indicated due to shortening or increasing the tone of the anterior muscles of the neck, especially in athletes.

In kyphosis, the posterior sections of the fibrous ring are stretched and this stretching leads to a decrease in the posterior protrusion of the disc. However, such a decrease in protrusion is possible only if it is small and if the fibers of this ring remain intact. When the fibers of the fibrous ring are torn, the prolapse of the intervertebral nucleus when bending the body forward usually does not decrease, but increases.

Thus, the lumbar kyphotic position can only partially and only under certain circumstances be considered as a protective compensatory one, providing for the reduction of the protruding fibrous ring and the reduction of irritation of the posterior longitudinal ligament or even the reduction of the root compression. It should be taken into account that with kyphosis, the posterior longitudinal ligament, as well as the posterior sections of the fibrous ring, are subject to stretching. The capsules of the intervertebral joints are subject to the same stretching. If flexion were exclusively a “protective” position, it would be difficult to understand why patients with the “syndrome” of lumbar osteochondrosis are so afraid of this position: with additional forward bends of the body (especially during physical exercise), lumbar pain and leg pain increase. Moreover, forward bends are one of the most well-known positions that provoke the disease. That is why, when bending forward and stimulating the receptors of various tissues of the spine, in some cases there is a reflex contraction of the muscles - the extensors of the lower back with fixation of the reverse pose - fixed hyperlordosis. Whether this extensor pose or flexor pose will prevail, all other things being equal, depends on which of the two reflexes is predominant.

Fixation of such a position is accompanied by severe pain; it also aggravates possible radicular compression. However, moderate kyphosis or straightening of the lordosis is a more favorable position (it is not for nothing that traumatologists and neurosurgeons artificially create this position during spondylodesis operations). It is formed more often than others not because of its "expediency", but because of objectively developing conditions in patients suffering from osteochondrosis of the lumbar spine.

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