Dispelling the Myth: Why Intervertebral Discs Do Not Slip

As physiotherapists, we often hear patients describe their back pain as a "slipped disc". This term has become common parlance, but it is important to understand that intervertebral discs do not actually slip. In fact, the term "slipped disc" is a misnomer that can lead to confusion and misunderstanding of the underlying mechanisms of spinal injury.

The intervertebral disc is a complex structure that serves as a cushion between the vertebrae of the spine. It is made up of two main components: the annulus fibrosus and the nucleus pulposus. The annulus fibrosus is a tough, fibrous outer layer that surrounds the nucleus pulposus, which is a gel-like substance in the center of the disc. Together, these structures provide shock absorption, stability, and flexibility to the spine.

The intervertebral discs are connected to the vertebrae above and below through a complex system of ligaments and joints. The vertebral bodies are separated by the intervertebral discs, which act as the primary load-bearing structures of the spine. The anterior longitudinal ligament runs along the anterior surface of the vertebral bodies and discs, providing stability to the anterior aspect of the spine. The posterior longitudinal ligament runs along the posterior aspect of the vertebral bodies and discs, providing stability to the posterior aspect of the spine. Additionally, there are ligamentous structures that connect the spinous processes and transverse processes of the vertebrae, contributing to overall spinal stability.

When a disc is injured, it is not the disc itself that has slipped out of place. Rather, the nucleus pulposus may bulge or herniate through a tear in the annulus fibrosus. This can put pressure on nearby nerves, causing pain, numbness, or weakness. The disc may also degenerate over time, leading to a loss of height and stability in the spine.

So why do we still use the term "slipped disc"? Part of the reason may be due to historical terminology, but it may also stem from the fact that a disc herniation can cause symptoms that feel like the disc has moved out of place. This can lead to a perception of the disc as a separate, mobile entity rather than a fixed component of the spine.

As physiotherapists, it is important to educate our patients on the true nature of disc injuries and to avoid using terminology that may perpetuate misunderstandings. Instead of "slipped disc", we can use more accurate terms such as "disc herniation" or "disc bulge". This can help patients understand the underlying mechanisms of their pain and improve their compliance with treatment.

In addition to accurate terminology, physiotherapists can also use evidence-based interventions to treat disc herniations. These may include manual therapy, exercise therapy, modalities such as heat or cold, and education on proper body mechanics and posture. In some cases, referral to a specialist or imaging studies may be necessary to rule out more serious conditions.

In summary, intervertebral discs do not actually slip, and using terminology such as "slipped disc" can perpetuate misunderstandings of spinal injuries. The intervertebral discs are connected to the vertebrae through a complex system of ligaments and joints, and contribute to overall spinal stability. As physiotherapists, it is our responsibility to educate our patients on the true nature of disc herniations and to use accurate terminology to improve understanding and compliance with treatment. By utilizing evidence-based interventions, we can help