Most people will have heard of a ‘slipped disc’ but what does this actually mean?
Usually this refers to damage or bulging rather than slippage or movement.
We have 23 discs in the spine situated between each adjacent vertebra – 6 in the neck, 12 in the upper/middle back and 5 in the lower back.
The intervertebral discs consist of an outer fibrous ring surrounding an inner gel-like centre. The outer layers of fibrocartilage provide strength to withstand compressive forces whilst the inner gel centre helps to distribute pressure evenly across the disc and also acts as a shock absorber.
Injury is very common due to the high loads placed on the discs. Most injuries (90%) occur in the lower back with the most common age group 30 – 40 years.
What causes the disc to bulge?
Disc bulging is most commonly due to age related wear and tear.
With age the intervertebral discs’ inner gel-like substance begins to dehydrate. The reduced fluid content within the discs make them stiffer, flatter and less able to shock absorb and therefore more prone to damage. Any strain or trauma increases the pressure on the disc’s central core, stressing and stretching the outer fibrous ring. If this is repeated over an extended period of time the disc can deform and bulge. In severe cases the inner gel substance can leak out.
Who’s at risk?
Risk factors for disc bulges include:
- Occupations that require repetitive lifting, bending, standing or driving
- Improper lifting techniques
- Participation in contact sports
- Severe trauma, such as a car accident
The disc bulge may compress the nearby nerve resulting in pain, pins and needles, numbness and weakness. The site of these symptoms depends on the level of the nerve being compressed. Interestingly, not all bulging discs cause pain. A review of 3110 asymptomatic individuals found that 60% of 50yr olds had disc bulging (Brinjikji et al 2015).
What can be done about a bulging disc?
The good news is that bulging discs can often heal on their own or after engaging in conservative treatments. Following a disc bulge the protruding disc material initiates inflammation and triggers an immune response. Immune cells engulf and digest the cellular debris and resorb the bulging disc material. How quickly this occurs and to what extent varies widely from person to person, depending on overall health, genetics and whether their movement patterns continue to provoke the disc herniation.
In all cases self-care advice should be followed including correct lifting of heavy objects to protect the back, maintaining a healthy weight and regular exercise to strengthen the back and core muscles.
Conservative treatment options to encourage disc healing and provide pain relief include:
Rest from manual labour and heavy lifting to avoid re-irritating the injury, whilst trying to remain as mobile as possible.
Whilst resting apply ice to the back to ease the pain, decrease any swelling and reduce the inflammation. For more information on ice vs heat click here.
Pain from a disc bulge can cause the surrounding muscles to go into a reflex protective spasm. Soft tissue massage can help relax these muscles, improve circulation and blood flow to the area to encourage the healing process.
Spinal mobilisations and manipulations can be applied with the goal of improving functionality, reducing nerve irritability and restoring range of motion in the spine thereby reducing any excess pressure on the intervertebral disc.
Nerve flossing involves specific stretches aimed to release the compressed nerve. The inflammatory process may result in adhesions along the nerve preventing the nerve from gliding smoothly therefore flossing can breakdown the adhesions and ease symptoms.
Walking and any other exercise that doesn’t cause pain should be continued. A specific rehabilitative stretching and strengthening exercise program is important to support the spine, keep the muscles in balance and improve overall mobility. Continuing these exercises even when the pain has gone is key to prevent reoccurrence of the problem.
Good Lifting Technique
When lifting heavy objects begin by squatting, keeping your back straight. Hold the object with both hands, keeping it close to your body, and slowly straighten your legs as you lift. Most importantly do not twist! If you need to place the item to the left or right, turn your whole body so that you are square on and then lower.
Disc bulges can be extremely painful and debilitating. Your GP can help by prescribing pain relief, muscle relaxants and anti-inflammatory medications.
If conservative treatment fails to resolve the problem other options include corticosteroid injections to reduce inflammation and swelling around the disc bulge and relieve pressure on the nerve root. The final option for those still experiencing pain and weakness is surgical correction of the bulging disc.
Recovery time varies from person to person but the good news is the majority of patients recover from a disc bulge within 3 months of conservative treatment.