Acute low back pain can be excruciating. Most of us, at some time, have suffered a bout – in fact, a whopping 87% of New Zealanders will experience back pain in their lifetime. That’s almost 9 out of 10 of us!
We frequently treat patients who tell us they’ve “slipped a disc”, or had their back “go out”, but what does that really mean?
To understand back pain (and these terms) better, it helps to have some knowledge of the back’s structure and how it works.
Let’s start with the basics. The spine is a bony column made up of lumbar vertebra in the lower back, thoracic vertebra in the mid back and cervical vertebra in the neck.
In between each vertebra is a disc that gives the spine flexibility and acts as a shock absorber. (In reality these can’t “slip” or go “out” of place as they are fixed to the bones above and below).
Discs are made up of a tough, outer ring (annulus) that surrounds a soft liquid nucleus.
There are small facet joints connecting the vertebra on each side. There are also ligaments that support the spine at the front, back and in between the facet joints.
Muscles run up either side of the vertebra, holding us upright and allowing us movement.
What causes back pain?
Back pain can be caused by damage or inflammation in any of the above structures, but disc injuries are especially common.
Disc injuries can occur from a sudden trauma/injury.
More often we see them in people who perform frequent, incorrect movements or lifting, as well as in people who spend a lot of time sitting.
Sometimes a person may have some degenerative disc disease that can also predispose them to it.
What is a ‘slipped disc’?
“Slipped disc”, or a disc prolapse/herniation as it’s medically known, often happens in the lumbar region.
It’s caused when the disc annulus is ruptured or torn and the nucleus pushes outwards. This can happen to varying degrees, from a slight bulge to a complete herniation where some of the nucleus sits right outside the disc.
Signs and symptoms of a disc injury
When this happens the disc bulge/herniation can put pressure on surrounding structures like nerves.
As a result you might experience:
- Pain in the back and leg
- Numbness/pins and needles/sharp pain in the foot or leg
- Loss of strength of some leg muscles
Where exactly in the leg you feel these symptoms will depend on which level of the spine is affected.
A suspected disc problem is often based on a patient’s history and symptoms, but an MRI scan is used for definitive diagnosis.
In more serious cases a disc herniation can affect bladder and bowel function. If this happens head straight to your GP or emergency department.
Preventing disc injury
Our number one aim is to help people avoid this type of injury altogether. There’s some simple ways to do this:
- Avoid repetitive bending and twisting movements, especially when lifting
- When lifting objects, hold them close to the body to minimise loading on the spine
- Brace the abdominals when lifting
- Avoid sitting for long periods, take regular breaks
- If working at a desk, consider using a standing desk (at least intermittently)
- Keep yourself fit and strong with regular exercise and specific strengthening
- See a physio for regular back care maintenance
Can physio help a disc injury?
There’s plenty physiotherapy can do to help.
Education plays a large part, especially understanding the importance of back care, posture and activity.
Many different forms of pain relief can be explored, including massage, acupuncture, manual techniques and hydrotherapy. Strength training can help support the back. Often these modalities work best in conjunction with pain-relieving medication, prescribed by a GP or specialist.
If, after at least 6 weeks of treatment, symptoms have not improved or have worsened then a referral to a spinal surgeon is routinely recommended.