Understanding Disc Bulges

Disc bulge, commonly referred to as herniated nucleus pulposas (HNP) is a condition that relates to the spine. HNP can be caused by immediate trauma or injury (sports injury, auto accidents, etc.), as well as long term trauma (improper posture). Discs are located between each of the vertebral bodies of the spine. The discs are the shock absorbers of the body. They also help to give the spine more movement and flexibility as we twist and bend.

The discs are shaped like a hockey puck and are made up of cartilage, which is tough and leather-like. Each disc is made similar to an onion, in that they are layered in rings (the annulus). At the very center of each disc is a watery, gelatin-like center. This center is called the nucleus. In general, the discs have a high content of water and this is what gives them their flexibility. As we age, the discs lose some of their water content and become less flexible. This makes the layers of the "onion skin" more brittle and weaker.

As we participate in activities that place us in a bent or "flexed" position (sitting, driving, reading, watching TV, etc.), the low back can lose its natural curve and pressure from the nucleus can be exerted on the back side of the discs. Over time, one layer at a time of the "onion skin" (annulus) splits or cracks and the gelatinous center moves closer to the outside. Eventually this nucleus begins to distort the shape of the disc causing the disc to bulge. This can happen to the direct backside but most often is slightly to one side or the other (in rare cases the bulge can be on the front side).

The pain is caused because the back side of the disc has many nerves. Another factor is that the spinal cord is directly behind the disc and as the bulge increases, it begins to irritate the nerves that are attached to the spinal cord. In the low back, these nerves travel down the leg. This can cause feelings of pain as far down as the foot and toes, as well as numbness or tingling in the leg and foot.

One way to help with this problem is by beginning extension exercises. By arching the low back, pressure can be taken off the back side of the disc. If this is done with frequency, the layers of the annulus can begin to heal and can form scar tissue. As the disc heals, the bulges reduce in size and take the pressure off the nerves, decreasing or eliminating the symptoms.

Another item that can keep the low back in its proper curve is a lumbar roll. The lumbar roll is placed behind the low back while you sit, and helps keep the back in its proper curve.

Your doctor of physical therapy will show you the exercises best suited to your situation and if you have further questions make an appointment today!