According to the figures recorded in France, the origin of back pain is poorly identified in 95% and 5% of people over thirty years of suffering back pain not relieved by medication. Therefore maintaining a healthy back is essential, especially when we know that this part of the body is stressed due to slopes from 1500 to 2000 every day.
The term back pain is any pain sitting in the spine or near it, whatever the origin, nature and intensity of pain. According to the origin of pain, there are the neck, back pain and back pain. These are the most common, especially among manual workers, while the neck affect more people working in offices.
In France, back pain affects 80% of people significantly at least once in their life. If the annual incidence varies with age, it seems less important in the age group of 20-24 years (4-18%) and highest in the age group of 55-64 years (8 to 32%).

The etymology of the word comes from the spine or ράχις ράχη Greek, meaning "back, backbone, and was formerly for spelling Rhachi to remind the rho. The vertebrae are the bony elements of the spine, or backbone. According to those, there are only 32 or 34. Given their constitution, they stack perfectly on top of each other to form the spine.

The spinal segment
A typical vertebra consists of a vertebral body with a core of spongy bone surrounded by a thin layer of cortical bone. The top and bottom of the vertebral body are delimited by the plates, relatively flat surfaces. Behind the vertebral body, the pedicles and the blades form the vertebral foramen leaving passage to the spinal cord. The joint between two vertebrae is achieved by means of the intervertebral disc and facet joints. The intervertebral disc is inserted between the plates of two adjacent vertebrae, plays a role absorber and allows a good distribution of loads and pressures. It consists of a nucleus pulposus and annulus fibrosus of a. The nucleus is a gelatinous structure composed largely of water which makes the drive the ability to absorb shocks and protect the column of significant efforts and repeated while the annulus fibrosus is a cartilaginous structure surrounding fibrous multi-oriented the nucleus to contain it perfectly.
On each side, the foramina allow the passage of nerve roots from the spinal cord to reach different parts of the body.
The intervertebral disc is composed of cells representing 1-5% of its volume, water and extracellular matrix. The role of cells is vital because they secrete extracellular matrix components, mainly collagen and proteoglycans, and enzymes, degradation agents. They are responsible for maintaining and renewing the matrix.
Cells need nutrients to function. But their supply is difficult because the intervertebral disc of the adult is not vascularized. Some cells can be up to 8 mm from the nearest blood vessel. However, preservation of adequate nutrition is essential because cells are responsible for the renewal of the extracellular matrix during life and thus indirectly to the maintenance of biomechanical properties of the intervertebral disc.
Variations in nutrient concentration, pH, mechanical stresses and the rate of cellular demand can stimulate or inhibit cellular activity.

The different levels of the spine
The spine is divided into five regions: the cervical spine, thoracic spine, lumbar spine, sacrum and coccyx. For each level is a numbering system adopted increasing from top to bottom.

* The cervical spine in the neck

There are seven vertebrae C1 to C7 named. The first cervical vertebra is the atlas C1 and has a circular shape and function to support the skull. The second cervical vertebra C2, the axis has a tooth or "odontoid process" pivot on which the atlas and the skull. C1 and C2 are often called upper cervical region and C3-C7 cervical region below.

* The thoracic spine in chest

It includes twelve vertebrae named T1 to T12. The thoracic spine is especially stable and strong due to the presence of his lengthy "process thorny" and it is connected to the rib cage. Nevertheless, some ribs are not connected to T11 and T12: these are floating ribs.

* The lumbar spine in the lower back

It includes five vertebrae named L1 to L5, which grows in size from L1 to L5. The vertebrae in this region are indeed the largest and most resistant of the column since they carry and distribute the bulk of the weight and stresses the body both at rest and in motion. Compared to the thoracic region, the pedicles are larger and longer and the spines are larger and square.

* The sacrum in the pelvis

It is located below the basin and consists of five fused vertebrae named S1 to S5.

* The coccyx

Three to five vertebrae that make up the coccyx are located at the tip of the spine. These bones have the same shape as the other forming the spine: it is solid bone with no holes from which the nerves to reach the other parts of the body.

Levels of curvature
From the side, the spine has four curves anatomical two lordosis (curvature concave rear) at the cervical and lumbar kyphosis, and two (concave curves ahead) at the thoracic spine and sacred. The reverse curves correspond to the hinges of the spine, joints that are predominantly loaded during movements of the spine. We distinguish the cervico-thoracic T1-C7, the lumbo-thoracic T12-L1 and hinge sacro-lumbar L5-S1.
These physiological curves and the muscles and ligaments of the spine equilibrium condition.

Spine pillar of the body is connected to surrounding structures: the ligament system, muscular system and vasculature.

* The system ligament and muscle

Each vertebra articulates with the vertebra above and behind (except the atlas and caudal vertebrae). The vertebrae are articulated by three joints, the intervertebral disc and two posterior apophyseal joints Inter. The strength is mainly provided by the spinal ligaments and muscles antagonistic movement. In addition to the complex corporeal disco or disco-somatic inter-apophyseal joints and posterior intervertebral ligaments and muscles are part of the vertebral segment spinal arthritis, a complex joint system making possible the movement of the spine.
In addition, the spine is the insertion and anchoring muscles to posture and the neck he received much of céphalogyres muscles that move the head.

* The vascular system

The spine has its own vascular system. It is located near many vessels such as the vertebral artery, the inferior vena cava, renal veins and thoracic aorta, which continues through the abdominal aorta, the anterior radicular artery of Adamkiewicz and the sympathetic nerve plexus .

The intervertebral disc undergoing changes over the events and life.

* Biochemical Events

The main biochemical event is the decrease in the rate of cell renewal. About 90% of the cells are alive in the disk of a healthy teenager, against 46% at the age of 44 years and 27% at age 57 years. Similarly the vertebral disc is composed of 90% water at 10% growth against 60.

* Events morphological

The morphology of the intervertebral disc changes during degeneration. At first it is spongy and firm. The first changes that affect the annulus weakens, then begin to develop small cracks. Over time, the disc loses water, it becomes smaller and loses altitude. Accordingly, the adjacent vertebrae move and approach each other. The intervertebral space decreases, the facet joints are found more and more compressed, the result is a pressure at their surfaces. Eventually, the facet joints undergo damage up to arthritis.
These changes within the disc, facet joints and ligaments lead to instability of the spine. Every movement is a source of additional wear and increased aging of the spine. In fact, cracks in the annulus grow in number and importance.Le nucleus can then pass through the damaged annulus and introduced into the spinal canal. This phenomenon is known as a herniated disc (see § 2.1.1). The party pushed out of the disc is in contact with the spinal nerves, which is a primary source of pain or warning to the patient. In addition, the disc releases enzymes and chemicals that produce inflammation and a new source of pain, which become increasingly intense. In addition to this degeneration, osteophytes grow but nobody really knows the cause, some doctors argue that it is a body's response to try to stop the movement induced between the spinal segments. These osteophytes can cause problems by exerting additional pressure on the nerves through the intervertebral foramen. The pressure around the irritated nerve roots can cause pain, numbness and weakness in the lower back, buttocks, legs and feet. Finally loss of mobility and stiffness of spinal segment, thickening of ligaments and facet joints, the drying of the disc and the presence of osteophytes are factors preventing normal movement. Paradoxically, a stiff joint does not cause pain so intense that a joint that "floats", despite the progress of degeneration, some people may feel relief.

Excluding mechanical trauma, the phenomenon of degeneration is related to aging. However its severity is modulated by genetic inheritance and environment. Disc degeneration usually begins during the second decade and only gets worse over time. At the age of 49 years, 97% of lumbar discs show signs of degeneration. This degeneration may be aggravated in some individuals because of their genetic heritage. Environmental factors promoting degeneration include smoking, exposure to vibration, port charges and repeated heavy physical activity.

The elderly are the most affected by degenerative diseases. However, as we have already seen, certain factors "at risk" such as obesity may accelerate the wear process.

Disc herniation
By stage of degeneration, one can observe two types of cervical disc herniations:

- The cervical disc herniation "soft" at an early stage of degeneration.
- The cervical disc herniation "hard" at an advanced stage.

The first stage of degeneration may be linked to the appearance of tears in the annulus as a result of normal wear and tear on the disc or a sudden injury due to twisting or excessive deformation of the disc, surpassing the resistance of the annulus. Pain in the back raised remain until healing tears. However, multiple lacerations weaken in no small disk, which then begins its degeneration. The collapse of the disc causes compression of the vertebrae, it no longer performs its function of shock absorber between the vertebrae. This sort of problem causes primarily a mechanical back pain. The weakened disc can then trigger a slipped disc. If the annulus tears, the material in the nucleus can escape the disc, causing compression of a spinal nerve in addition to inflammation of the nerve root. The pain then the key areas through which the nerve to the leg. This is sciatica.

Arthritis, cartilage wear can affect any bone in the human body. For the spine we talk more specifically spondylosis or osteoarthritis when it induces a loss of cartilage, bone overgrowth and formation of osteophytes at the facet joints. Generally, intervertebral discs are the first part of the spine to wear, so people suffering from spondylosis are also experiencing problems of degeneration in their spinal discs.

* Spinal Stenosis

Spinal stenosis refers to lower section of the lumbar spinal canal where the spinal cord passes. The spinal cord ends at L2. Below, the spinal canal contains only the spinal nerves that pass through the pelvis and legs. When the stenosis reduced the spinal canal, spinal nerves are then compressed within it. This results in pain and numbness in the buttocks and legs and weakness of muscles supplied by the nerves involved. Since the nerves pass through the bladder and rectum, poor bladder control and bowel may occur: it is an emergency. If the pressure is not dissipated, it can cause paralysis of the bladder and intestines. Doctors recommend immediate recourse to surgery to relieve compressed nerves.

* Foraminal stenosis

The spinal nerves exit the spinal canal between the vertebrae in a tunnel called intervertebral foramen. We are talking about when foraminal stenosis narrows the intervertebral foramen due to the collapse of a disc. Induced loss of height causes the collapse of the vertebra above the disc to the one located below it: the opening between the vertebrae narrows to compress the nerve. The phenomenon of arthritis in the facet joints leads to the formation of osteophytes which will tend toward the foramen, causing additional compression and irritation. Foraminal stenosis may cause a "double pain", mechanical and neurological from irritation of the nerve root.

Conservative treatment
As soon as possible, doctors prefer to use treatments other than surgery. These so-called conservative treatments aim to relieve pain and other symptoms. When back pain occurs, it is suggested, first, follow some simple guidelines in the home, allowing for 90% of returning things to normal after one month:

- Sleep with a pillow between your knees and lie on the side improve comfort. Some doctors recommend to lie on his back and put a pillow under your knees.
- There is no specific exercise against backache to improve the condition of people suffering from acute pain. However, it may be useful for people suffering from chronic pain and help them return to their activities and their work.
- Drugs without prescription need, such as ibuprofen and paracetamol are excellent for short-term treatment of low back pain.
- The use of ice or warm compresses may help some people, although their effectiveness has not been proven.
- Most experts agree on the fact that bed rest is associated with a longer recovery period. In addition, people are more likely to develop depression, blood clots in the legs and decreased muscle tone.

There are many kinds of drugs commonly prescribed to try to control back pain. However, none can cure back pain. The drugs are the main objectives of reducing sleep disorders and pain control, inflammation and muscle spasms.

* Analgesics Level 1

This is paracetamol and anti-inflammatory drugs such as ibuprofen. The long-term use may be associated with gastric irritation, kidney problems.

* Muscle relaxants

Muscle spasms are not considered as a cause of back pain and most of the muscle relaxants have no effect on muscle spasms and are no more effective than analgesics. They cause drowsiness in 30% of cases and their regular use is recommended.

* Analgesics

These drugs are considered an option for control of acute pain and are associated with serious side effects such as dependence, decreased reaction time, nausea and confused judgments, in a large percentage of the population taking more a few days the most noticed is constipation. Some studies report their effectiveness in the short term pain relief. However, their use does not accelerate recovery.

* Steroids

Oral form, they can be beneficial for the treatment of acute sciatica. As epidural injections, it has not been proven that this substance has the power to decrease the duration of symptoms or improve the patient's condition and are not recommended for the treatment of acute pain without sciatica. The perceived benefits in chronic pain with sciatica remain controversial. Injections into the joint spaces, facet joints can be beneficial to people suffering from sciatica. It has never been proven that the "trigger point injections" are effective in acute pain but the combination of a steroid and a local anesthetic may be useful in cases of chronic pain. Their use remains controversial.

See also Osteoporosis