Low back pain is very common and something we see a lot of here at Ashlins. Although back pain can be alarming and debilitating, most cases are due to muscle or joint problems and often resolve within 6 weeks. Many sufferers find it reassuring to understand the anatomy of their low back as it helps them visualise and rationalise their symptoms and the healing process.
Your low back contains 5 large bones which make up the Lumbar spine. In descending order they are named L1-5.
The bones in your low back are larger than you think. They are around 8 cm deep and 2-3cm tall. The bones get bigger as you travel down the spine.
When you run your fingers down your back you can feel knobbly bones sticking out. Those are your ‘spinous processes’ and are the tip of each vertebra.
Vertebrae aren’t the only thing in your spine though. Between each bone you have a disc (or intervertebral disc to give it the full name). The discs are named according to the bone above and below, for example L4-5. Discs help give your spine flexibility.
You also have 2 facet joints between your vertebrae, one on the left and one on the right. They help support your spine.
In addition, your back is supported by ligaments (attach bone to bone), muscles and tendons (attach muscle to bone).
There are a lot of muscles that support and control your low back. Some of them are quite close to your skin and relatively easy to feel. Others are deep inside the body. Some are large and powerful, others are much smaller but still important. Muscles in your pelvis, legs and abdomen are also important for your low back.
Your low back supports your body, allows you to move, and protects your spinal cord. The spinal cord is a bundle of nerves running down your back. Between each of your vertebra, a bundle of nerves exits the spine on each side. We call this the nerve root. Those nerves continue their journey around your body and supply your muscles, joints and skin.