The Spine

The vertebral column (backbone, spine) – extending from the skull to the coccyx – forms the skeleton of the neck and back and the main part of the skeleton (the articulated bones of the skull, vertebral column, ribs, and sternum). Most vertebral columns in adults are 72 to 75 cm long, of which about one-fourth is formed by 4 discs, which separate and bind the vertebrae together. The vertebral column:

§ protects the spinal cord and spinal nerves,

§ supports the weight of the body,

§ provides rigidity, flexibility and stability for the body and the head,

§ plays an important role in posture and locomotion – movement from one place to another.

The range of movements of the vertebral column varies according to the region and the individual. Movements of the vertebral column are freer in the cervical and lumber regions. Flexion, extension, lateral bending, and rotation of the neck are especially free. Movements are extraordinary in some people, such as acrobats who begin to train during early childhood. The mobility of the vertebral column results from the compressibility and elasticity of the intervetebral discs. The following movements of the vertebral column are possible: flexion, extension, lateral bending, and rotation.

The Vertebral Column

The vertebral column in an adult typically consists of 33 vertebrae of five regions: 7 cervical, 12 thoracic, 5 lumber, 5 sacral, and 4 vertebrae of the coccyx.

Motion occurs between only 24 vertebrae: cranial, thoracic and lumber. The five sacral vertebrae are fused to form the coccyx. The vertebrae gradually become larger to the sacrum, and then they become progressively smaller to the coccyx. The vertebral column is flexible because it consists of many small bones – the vertebrae – that are separated by intervetebral discs. Although the movement between each two vertebrae is small, a column is flexible, rigid and stable.

The back muscles produce movements of the vertebral column. But these movements are not produced only by the back muscles. They are assisted by gravity and the action of the anterolateral abdominal muscles.

Although movements between adjacent vertebrae are relatevely small, especially in the thoracic region, the summation of all the small movements produces a considerable range of movement of the vertebral column as a whole (e.g. when bending to touch the toes).

Movements of the vertebral column are freer in the cervical and lumbar regions than elsewhere.

Дата добавления: 2015-09-05