CAUSES

What Causes a Bulging Disc?

When a bulging disc, disc herniation or disc rupture occurs, it is typically due to either:

• a pre-existing weakness in the annulus, or
• a sudden increase in pressure through the disc causing fibres of the annulus to tear. 

The causes of disc injury can be summarised under three headings:

1. Accumulated Microtrauma

Repeated microtrauma over an extended period can lead to disc injury. The best example of accumulated microtrauma is poor posture.

Poor posture when sitting, standing and working stresses your spine. Sustaining a slouching or forward bending of your spine leads to overstretching and weakness of the posterior fibrocartilage (or annulus) of the spinal discs. Over time, this leads to poor disc integrity and displacement of the disc nucleus fluid posteriorly. This places your spinal joints and nerves under pain-causing pressure.

To decrease the effect of poor posture on your spine it is important to continually attempt to a maintain a good posture or even better, regularly change your posture. 

During your initial efforts to retrain a good posture, poor muscle endurance and posture awareness predisposes you to sag back into your old habits. In these instances, it is useful to note that supportive posture devices such as a lumbar roll, Basset spine support, kinesio taping or a back brace are available to help you maintain a lordotic curve to your lumbar spine during this transition phase.

Any sustained posture should be regularly altered to allow your spine to move and remain healthy.

2. Sudden Unexpected Load

Sudden unexpected load to the intervertebral discs can also occur in traumatic situations, ie: a motor vehicle accident. This may happen due to the nature of the sudden forces exerted through your body at the time of impact and your bodies attempt to repel those forces. 

Unexpected load or torsion of a disc can result in tearing of the annulus fibres and hence a disc injury. You should always lift any amount of load using the correct postural lifting principles. Using poor lifting techniques, such as bending forward and pulling with your back may result in sudden and unexpected loading of the disc. 

Ask your physiotherapist about these principles.

3. Genetic Factors

As with many conditions spinal disc injury is considered to have a genetic predisposition. 

Those suggested to be susceptible are people who are known to have a lesser density of and increased elastin component of the fibrocartiliginous fibres, which make up the annulus of the intervertebral disc. Other factors that play a role are more environmental in nature – such as excessive abdominal fat, poor core stability, poor lower limb strength, nature of occupation (ie: heavy physical load versus light or no physical load). 

Overall, genetic factors are a very minor contributing factor in disc injuries and if one does sustain a disc injury it can almost never be put down to ‘genetic factors’. And, let’s be honest, you can’t change your genetics. All you can do, is be more diligent in your back injury prevention.