Low back pain

The amount of lower back pain we feel can be affected by how much tissue is injured, what sort of load and stress we put through our lower back day-to-day and last but not least, our mood and stress levels.

Pain is our body’s response to how dangerous it thinks a sensation is/how much danger it feels we’re in. If it feels things are highly dangerous, it will try to stop us moving the area it thinks is under threat by making us feel pain. Stress adds to that feeling of being under threat, and combined with the information our body is receiving from the injured area, this will naturally increase the level of pain our body makes us feel.

Here’s the 3 main causes of lower back pain:

Muscles

If our muscles are very tight, have been working overtime, or have been strained by too heavy a load being put through them, they can become painful to stretch and tender to touch. If any muscle fibres have been damaged, regeneration normally starts 4-5 days POST injury and peaks at 2 weeks.

If our muscles are tight, overworked and constantly irritated then we would need to look at altering our Biomechanics, learning how we move and how to best reduce the load on that muscle or group of muscles.

Joints

Our spinal joints are called zygapophyseal joints or facet joints and are positioned at the back of our vertebrae (bones of the spine). Along with the disc, they allow the spine to move and stabilise the joint.

Pain from our facet joints tends to be felt either side of the spine, both locally and radiating to the legs or groin. It is often set off by activities that involve leaning backwards, as this is a position that loads the joint.

Facet joint pain can also be caused by arthritis and/or obesity making the joints sore and inflamed. Our posture, particularly those of us with a big arch in the back, can suffer facet pain as it is a position where the joints are continuously being loaded at the end of their range (joints are designed to move through their whole range, but they may become irritated  if they’re often static at the end of range).

Facet pain can also be caused by a condition called spondylolisthesis. This is where the vertebrae (spinal bone) move slightly forwards on the one below it.

Treatment for facet pain can involve Physiotherapy to help change the biomechanical factors that are irritating the joints. Mobilisations of the joint and other manual therapy can help with stiffness and pain.

Discs

There’s a lot of unhelpful and potentially worrying phrases you may have heard related to discogenic (pain from the disc) pain. Discs are described as `popping out, slipping or even crumbling’. However, discs don’t actually do any of these things (though if your back is really painful it may well feel as if they have!). To explain why they can hurt it helps to explain a bit about their construction.

Discs are made of an outer and an inner part. The outer part is made of lots of layers wrapped around each other, rather like an onion. This outer layer is called the annulus fibrosis and it wraps all the way round. In the centre of the disc is a soft, jelly-like substance called the nucleus pulposus.

On top and bottom of the disc is a layer of cartilage

Fun fact – discs don’t have their own blood supply. They get their nutrition from the cartilage above and below them as well as the outside layer of the disc. Some of the nutrition (blood and oxygen) diffuses into the disc and some of it is `sucked in’ via movement of the disc (similar to a sponge being squeezed to draw water in and out).

Why and how can discs become painful?

Sometimes the outer part of the disc can become slightly damaged causing it to bulge out as the disc is under pressure. This can be painful as the body creates inflammation to repair the disc. It can also be painful if the disc bulge reduces the space around or bumps into a nerve passing nearby causing nerve irritation and pain.

Sometimes the damage is enough that there is a small tear in the disc and occasionally it can be enough of a tear for a small amount of the ‘nucleus pulposus’ to escape from inside the disc. This is made of a substance that is very irritating to the surrounding tissue and even a small amount can create a lot of pain.

Pain from the discs can be felt in movements that involve leaning forwards, twisting or sitting for more than 60 minutes, as these all increase the pressure through the disc. It can also be aggravated by coughing or sneezing as this increases pressure in the disc.

The good news? Discs often heal! While lower back pain can be incredibly frustrating and sometimes debilitating, it is VERY common. There are so many methods and therapies to help lower back pain so you mustn’t worry without seeing a Physiotherapist first.

If you have any issues with lower back pain, you can speak to our Physiotherapists for FREE advice using our online ‘Ask A Physio’ service, here.