What is a bulging disc?April 24, 2013
Back injuries are extremely common especially in an outpatient physical therapy setting such as Total Performance Physical Therapy. Low back pain patients generally make up approximately 50% of the patient profiles seen throughout the course of the day. Here are a few low back pain statistics for you:
- 60-80% of the population will experience low back pain at some point in their lifetime.
- 80% of people will return to normal activity within 4-6 weeks
- 60% will have their pain reoccur within one year
- 85 % will have their pain reoccur at some point in their lifetime.
As you can see from these statistics, low back pain is very common and the source of the pain cannot always be detected. However, when people go to get an MRI of their back, an injury commonly detected is a “bulging disc”. Doctors commonly refer to this injury as a herniated nucleus pulposis. Some other names include slipped disc, herniated disc, and ruptured disc. These bulging discs can also commonly occur in the neck and the principles are the same, but we will keep the discussion to the low back.
What is this disc doing that it is causing you pain?
Your back is composed of vertebrae (bones) interspaced by vertebral discs (fibrocartilage) that act together along with other components of your back to allow movement along with stability. The spinal cord is housed just behind the discs and vertebrae in circular column of bone, which contains small openings (foramen) that allow your nerves to exit to travel to the rest of the body.
The intervertebral disc can be thought of as a jelly donut. There are two components of the disc, the annulus fibrosis and the nucleus pulposis. The annulus can be thought of as the dough of the donut, which houses the jelly (the nucleus pulposis). When you squeeze one end of the donut, the jelly squeezes out of the other end.
A bulging disc can occur from a multitude of factors. Poor posture, trauma, aging, and improper lifting technique can all cause a bulging disc. Basically, an overly flexed posture of the back, such as from bending over to pick up an object from the floor or having a slouched posture, pushes down on the front of your disc. Over an extended period of time (except in the case of trauma) the jelly (nucleus pulposis) is squeezed out the other end. What awaits at the other end is your spinal cord and nerves. When the pulposis presses on these structures is when you begin to feel signs and symptoms consistent with a bulging disc.
Signs & Symptoms
Your signs and symptoms may vary depending upon what spinal level the herniation has occurred and what spinal nerves are involved. The majority of herniations (95%) in the low back occur at the L4-L5 & L5-S1 levels, which will affect your L5 and S1 nerve roots respectively. Signs & symptoms:
- One-sided leg pain below the knee that is greater than your back pain
- Radiating, shooting pain into your legs
- Numbness and tingling into your feet and toes
- Decreased sensation in your legs and feet
- Decreased strength in your legs and feet
These signs and symptoms will occur in a specific nerve pattern/distribution that a physical therapist can accurately assess. This injury is especially common amongst people ages 30-50 that may have an occupation that requiring a lot of lifting or requiring their back to constantly be in a bent over or rotated position. Activities such as standing make the pain better and activities such as sitting and bending make the pain worse.
A physical therapist understands the anatomy and physiology of the spine, the effects a bulging disc will have on a patient, and the treatment necessary to decrease and eliminate the sign and symptoms of a bulging disc. Physical therapists will use strengthening, posture correction, education, and repeated movements to decrease the effects of the bulging disc. It is important to understand the idea of centralization when it comes to a bulging disc. This is the idea of ‘centralizing’ the pain in your legs and feet back up to your low back. This indicates that the nucleus pulposis (jelly) is pushing and compressing less on your nerves. Since repeatedly bending over and/or twisting dislodged the disc material, the material needs to be put back in place by extending your back and thereby centralizing the pain to your low back. Physical therapists can show you many ways to execute these moves. Once the pain and symptoms are centralized the nerves need time to decompress for the pain to be completely relieved. Once the pain is gone it is important to strengthen the necessary musculature and teach each patient how to move properly. If these goals are not accomplished or ignored, then as the statistics above indicated, the pain will return.
If you have low back pain or find that this post speaks directly to you, visit Total Performance Physical Therapy for an evaluation.