Intervertebral disc

Intervertebral discs are located between the vertebrae of the spine. They are an important structure of the back. The intervertebral disc is often mentioned as the cause of back pain. People also think it has shifted during ‘throwing your back out’. Many people are also afraid that intervertebral discs are easily damaged. But is this really the case?

Anatomy of the intervertebral disc

Between two vertebrae of the spine lies an intervertebral disc, 23 in total. This creates space between the vertebrae so they can move relative to each other. In addition, an intervertebral disc provides stability and keeps the vertebrae together. There are no intervertebral discs between the highest cervical vertebrae and the lowest vertebrae at the tailbone.

The intervertebral disc consists of a strong outer ring of connective tissue, the annulus fibrosus. This ring has different layers. The ring surrounds the gel-like center of the intervertebral disc, which we call the nucleus pulposus. The gel-like material consists of loose fibers and proteins. The nucleus pulposus helps transfer pressure and protects the vertebrae against high loads.

The intervertebral disc is attached to the vertebra with an endplate . This endplate consists of bone and cartilage and is extremely strong. This makes it impossible for the intervertebral disc to slip away. Blood vessels in this endplate also supply nutrients to the intervertebral disc.

Function of the intervertebral disc

The intervertebral disc has a shock-absorbing function. The intervertebral discs absorb and distribute the forces applied to the spine. Due to its structure, the intervertebral disc can absorb both compressive and tensile forces.

An intervertebral disc consists mainly of water (80-85%). Many nutrients are dissolved in this water. The functioning of the intervertebral disc is determined by the quality of these components. Due to pressure on the intervertebral disc, nutrients are exchanged via the endplate with the blood in the body.

During high pressure, water is pressed out of the intervertebral disc. When the pressure is relieved, it can absorb water with nutrients and building blocks again. It works like a sponge. Regular loading is therefore of great importance. Thanks to new nutrients, the intervertebral disc remains of good quality.

Conditions

When the gel-like substance no longer transfers forces properly, complaints can arise. This occurs mainly when ambling and when sitting or standing in the same posture for long periods. This gives patients a feeling of stiffness in the back. In this case, there is too little fluid and too few nutrients in the intervertebral disc.

When the intervertebral disc retains too much fluid, there are mainly complaints of morning stiffness when bending over and putting on socks. Retaining too much fluid occurs when the ligaments around the intervertebral disc become lax. The ligaments then no longer compress the intervertebral disc. With insufficient pressure, there is less exchange of waste and nutrients, so the water remains in the disc. The water then also contains insufficient nutrients.

A well-known condition of the intervertebral disc is a herniation. In a herniated disc, there is a bulge of the soft core of the intervertebral disc. This leads to back pain. The symptoms can also radiate to one or both legs due to pressure on a nerve.

Recovery of the intervertebral disc

The recovery process is determined by the presence of sufficient nutrients. Under ideal conditions, recovery occurs automatically. There must be sufficient supply of nutrients. This supply is optimal when the spine moves well. A blockage or instability of the back can disrupt this.

Many problems of the intervertebral discs resolve on their own. When this is not the case, a physical therapist can help.

It is important during recovery to adjust the load to the load tolerance of the intervertebral disc. The healing time of the connective tissue in the intervertebral disc is a few weeks. The connective tissue around the intervertebral disc needs three months to recover. 

When the balance between load and tissue capacity is not good, no recovery can take place. The body then ‘searches’ for adjustments. This can result in spondylosis. Spondylosis is wear and tear of the spine. In this condition, the spine stiffens from the vertebrae. This stiffness compensates for the resulting instability. In addition, there will be adjustments in the posture and movement of the spine. As a result, recovery requires even more time. Recovery is also strongly age-dependent.

Rehabilitation for intervertebral disc complaints

In rehabilitation, loading is always movement-dependent, which means the back must be trained in different movements. Not only straight, but also sideways and with rotations of the back, depending on what the intervertebral disc can tolerate at that time.

Movement enables the exchange of nutrients. It is therefore important that all vertebrae move well again. By means of mobilizations or manipulations, any blockages are removed. If optimal recovery is no longer possible, the focus will be on achieving the right compensation. Even with compensation, completely pain-free movement is possible.