Which Type of Disc Bulge Do You Have?
Find out which type of disc bulge you have so you can make the correct steps forward in your recovery.
There are three categories of disc bulges. Understanding which type of disc bulge you have is important to take the most optimal steps forward in your recovery.
1. Small Focused Bulge
The first and most common type is a focused disc bulge. This is caused by repeatedly bending your spine in the direction away from the bulge. For example, if the bulge is on the posterior side of your disc and towards the right side then bending forward and to the left would promote the bulge (see my article here for a thorough breakdown of how and why bending leads to disc bulges).
People with this type of bulge generally can perform a certain number of tolerable bends before their pain occurs. The more load that is involved in bending (e.g. bending over to pick up something heavy), the less tolerable bends you can perform before the onset of symptoms.
To recover from this type of bulge you need to stop aggravating the bulge and allow it to shrink down in size. Learning to spare your spine and bend with your hips are important strategies to avoid aggravating this type of bulge and allow it to heal. Again, see my previously mentioned article for a more detailed breakdown of this pathology and the strategies to recover.
2. Reduced Disc Height
A different type of bulge can occur when a disc loses height. It is common for disc to lose height following certain injuries (such as damage to a vertebral endplate). Rather than the above type of bulge that only bulges out in one small location, reduced disc height can cause a disc to bulge out on all sides. Imagine letting some air out of a car tyre causing the flattened tyre to bulge under the weight of the car.
Another key difference between this type of bulge and a focused bulge is that bending does not promote this bulge. Instead, applying compression ("squishing" force) will cause the disc to bulge on all sides. For example, if you are carrying shopping bags or lifting something over your head this will add some compressive force to your spine. You can again imagine a car tyre that has had some air taken out of it. If you held this tyre up in the air it wouldn't be obvious that air had been taken out of it. However, the empty space inside the type will compress causing it to bulge under the weight of a car.
We can again continue with our tyre analogy to understand the consequences this type of bulge has. What does it feel like to drive a car with a flat tyre? You feel a bit unstable on the road, like you are not in complete control. The same thing is occurring in your spine. A flattened disc can cause instability and increased motion in your spine leading to pain. Symptoms can vary with this type of bulge and include central back pain as well as pain down different legs.
With this type of bulge, we need to identify the activities causing symptoms and eliminate them to get out of pain. Then we can build pain-free movement patterns and train improved stiffness and control.
3. Disc Tear
The third and final type of disc bulge is an annular tear. Our annulus is the outer ring of our discs that contains the gel like substance within the discs centre. The annulus is made up of concentric rings of collagen that are woven together into a biological fabric. The many layers of this fabric can separate which allows the gel substance from the middle of the disc to leak into the spaces between the layers.
This type of bulge usually occurs with excessive twisting motions. To recover it is important to avoid twisting and with time the disc annulus will heal, and symptoms will reduce. The McKenzie side glide exercise can be effective in treating this bulge and reducing symptoms, however if significant height has been lost from the disc than it is often ineffective. If you are not noticing significant improvement after performing a side glide, it may be best avoided.