SPINAL COLUMN

The spinal column is the organ which directly supports the body and shelters the most important nervous thoroughfare, which is why spinal disorders and deformities have frequent neurological impacts. The spine is made of 33-34 vertebrae, has 2 kyphotic curves and 2 lordotic curves.

Spine functions:

  • 1 - Support;
  • 2 - Defense (Protection);
  • 3 - Mobility;

Structural and functional element of the spine is spinal motor segment, which consists of two vertebrae, ligaments and intervertebral disc. Intervertebral disc is a complex formed by annulus fibrosis, similar to a retention bandage of nucleus pulposus, located inside the disc, which takes the effort on the column, in a way that it has also a retaining function, mobility and shock absorber.

Topographic description

The spine is anatomically divided into 4 regions:

  • 1 - cervical region, consisting of 7 vertebrae;
  • 2 - thoracic region with 12 vertebrae;
  • 3 - lumbar 5 vertebrae;
  • 4 - 5 sacral vertebrae welded and coccyx region consists of 4-5 vertebrae;

Thoracic region of the spine is less mobile than cervical and lumbar regions. The lumbar vertebrae are the highest and have the largest diameter to cope with the pressure exerted on them. The spinal column has 4 physiological curves located in the sagittal plane, which increases its resistance to vertical applications (approximately 10 times more than the same column without curves). Cervical and lumbar segments have anterior convexity, thoracic segment has a posterior convexity. Sacro-coccyx segment is an immobile curve with the posterior convexity. The curves, spinal ligaments and intervertebral discs help achieve an appropriate intrinsic balance of column, plus the extrinsic balance, realised by the muscles that support the spine directly, or through other structures. Thus, there are many mechanisms that serve to assign spine strength, mobility and maximum flexibility which make it suitable for a supporting role, focus, protection and movement.

"The backbone must be mobile as much that is possible and stable as necessary"

Gutmann

Column height decreases with aging and after prolonged static position, due to loss of water from the intervertebral disc, nourished by diapedesis. It is known that 15 minutes of horizontal position, restore the intervertebral disc height reduced in orthostatic position for 90 min.

The vertebrae are connected by two types of junctions:

  • 1 - syndesmosis between the vertebral body and intervertebral disc allows five types of movements (flexion, extension, lateral tilting, rotating around a vertical axis, slip between the vertebral bodies, removal and closeness between vertebrae);
  • 2 - facet joints allow anterior, posterior or lateral slides, depending on their spatial orientation;

Muscle tone is the state of static contraction, which is maintained by the reflector mechanism, plays a role in determining posture and joint stability. Hypotonus and hypertonus within physiological limits, don't cause significant changes, but beyond certain limits may initially cause spinal deviation and even then outstanding deformations. A well led training, muscle properties (tonus, excitability, contractility, elasticity, plasticity) can develop up to higher values.

Note: Cervical spine intervertebral discs represent approximately 30% of cervical spine height, and this largely due to nucleus pulposus containing up to 80% water for young people and 65% for old people. Property to capture water, which is due to chondroitin sulfate concentration, decreases with age. Depending on the effort and position, the nucleus pulposus changes its form (not the volume), and due to annulus fibrosis elasticity, the damping effect is obtained for the intervertebral disc and the entire spine. With age and degenerative pathology, annulus loses elasticity properties and ability to absorb the effort received from pulposus complex.