Lumbar disc injuries involve a large spectrum of severity and can produce multiple different symptoms. Some people will experience only low back pain while others may also experience pain, numbness, or tingling into the buttocks or down their leg. Although disc injuries can be very painful, the majority of them will resolve fairly quickly.
The interesting part of disc injuries is that the pain that is felt is not produced within the disc. Anatomic studies have found that there are no sensory nerve endings within the discs. The back pain that is felt is usually due to irritation of the ligaments that lie on the outside of the disc. Therefore, one of the keys to successful treatment is reducing this irritation of the ligaments.
The disc has two main parts to it – a jelly-like substance in the middle called the nucleus palposus and a series of fibrous rings that contain this nucleus. These fibrous outer rings are called the annulus fibrosus. When a disc degenerates or is injured traumatically, there can be some tearing of the inner rings of the annulus fibrosus. This allows the nucleus palposus to squeeze through the deficit in these inner layers. The end-result is pressure created on the outer rings of the nucleus. If this pressure builds to a high enough degree it can cause the outer edge of the disc to bulge.
A minor bulge can put pressure on the surrounding ligaments, producing low back pain. If the bulge is more significant, then it can begin to irritate the spinal nerve that exits the spinal cord behind the disc. This can lead to intense leg pain called “sciatica”.
Commonly what will happen instead is the release of chemical irritants from the injured disc material. These irritants can contribute to nerve inflammation that will produce symptoms in a leg such as numbness, tingling, weakness, or pain.
The goal of physiotherapy treatment is to reduce the pressure that the nucleus causes on the annulus fibrosus. Treatment may include exercises and hands-on techniques to encourage the nucleus material to move back toward the middle of the disc. A very important part of the treatment plan is education regarding positions or postures that can aggravate the disc injury. Positioning is key to alleviate the pressure within the disc and allow the surrounding tissues to settle down.
When diagnosed and treated appropriately, most disc injuries recover within a few weeks or months
without the need for surgery.