Anatomy of the Spine

The spine is a stack of axial skeletons; this framework provides a strong, but supple support for the body and the protection of the delicate mellow.

The vertebral column includes 33 vertebrae stacked vertically on top of each other. The vertebrae are connected by articulated facets at the back of the column. These joints allow movement between the bones of the column. The vertebrae are stabilized by ligaments and above all, are separated by an intervertebral disk located between each vertebra, functioning as a shock absorber.

The vertebrae can be classified into five groups. These groups include the 7 cervical vertebrae, the 12 thoracic vertebrae, the 5 lumbar vertebrae, the 5 fused sacral vertebrae and the 4 fused coccygeal vertebrae. The spinal cord runs through a canal located behind the vertebrae and extends from the brainstem to the lumbar region of the spine. The nerves branch off from the spinal cord, sending messages about movement and bodily functions to the rest of the body.



The vertebral column is composed of bone bodies (vertebrae), intervertebral discs serving as a buffer between two successive vertebrae, and associated elements (muscles, ligaments …) ensuring cohesion and mobility of the whole.

The vertebrae (33 to 35 in total) are divided into 5 groups:

  • cervical vertebrae,
  • the thoracic vertebrae,
  • the lumbar vertebrae,
  • the sacrum,
  • the coccyx.

Vertebras are moving elements along certain axes and amplitudes. They support very important efforts.

Components of the Spine

The vertebra: bone

Bone body

It consists of a cylinder that supports the main effort and apophyses, located at the rear, which limit the movement of the cylinder, to ensure the cohesion of the column.

The cylinder is massive, not very sensitive. It can get bogged down with age or fracture (a common consequence of osteoporosis).

The apophyses are rich in nerves and therefore very sensitive. The pain often concerns these processes, because of the too strong pressure on their cartilages.

The intervertebral disc

Located between two successive vertebral bodies, it acts as a damper disc. It is composed of concentric circular ligaments enclosing at their center a liquid core maintained under pressure. This structure realizes a real damper system between the vertebrae.

The damping quality of the disk is ensured by maintaining the pressure of the liquid contained in the core.

Associated Elements

Muscle capsule ligament,Ligaments, capsules and muscles connect the bone processes.

They provide stability and movement of both vertebrae. These structures are very sensitive, as for other joints of the body (knees, hip …).

These elements are most often affected by pain in low back pain.

Back and effort

Standing position

During the day, whether you are standing or sitting, the intervertebral discs are under heavy pressure.

These pressures are due:

  • to everything that weighs directly on the column: head, upper body, arm …,
  • mechanical stress associated with muscular efforts that pull on the column: movements of the arms, support of the abdomen …
  • Pressure intervertebral discs while standing


The vertical posture

Supported and stabilized by the muscles and ligaments that surround it, the spine helps to stand up


The alternating stack of flexible elements (the intervertebral discs, which represent 20 to 30% of the height of the mess) and hard (the vertebrae) gives a great mobility to the trunk.

The protection of the spinal cord

The vertebrae have a central cavity called vertebral hole, the superposition of which forms the spinal canal, or vertebral, which protects the spinal cord.



The vertebral column is composed of bone bodies (vertebrae), intervertebral discs serving as a buffer between two successive vertebrae, and associated elements (muscles, ligaments …) ensuring cohesion and mobility of the whole.

Pathologies and related issues

Back pain. It is defined as localized pain that usually originates in the spine and usually affects the muscle groups surrounding it. Low back pain is localized pain in the lumbar region. Sciatica, characterized by pain from the lower back and extending into the leg. Frequent, they are due to compression of the sciatic nerve that can sometimes be caused by the lumbar vertebrae. Different pathologies can be at the origin of these pains :

Degenerative pathologies. Osteoarthritis is characterized by cartilage wear protecting the bones of the joints.  The disc herniation corresponds to the expulsion behind the core of the intervertebral disc, by wear of the latter. This can result in compression of the spinal cord or sciatic nerve.

Deformities of the spine. Deformations of the column may occur. Scoliosis corresponds to a lateral displacement of the spine. Lordosis is associated with an accentuated arch in the lumbar vertebrae.

Lumbago. This pathology is due to deformities or tears of ligaments or muscles located in the lumbar vertebrae.