In Australia the vast majority of people (around 80%) will have lower back pain at some point in their lives.
In most cases lower back pain (sometimes referred to as 'lumbago') gets better without any medical treatment, however some cases may require some form of treatment which ranges from over-the-counter medication for pain and inflammation to physical therapy to a variety of spinal injections.
Opioid medications should not be used for most forms of back pain, and surgery should only be reserved for significant structural or medical problems causing back pain.
Symptoms of lower back pain can be anything from mild pain to severely disabling pain, along with difficulty moving your back (i.e. bending, twisting). The pain can be anything between a dull ache to stabbing pains and it may be accompanied by a feeling of weakness, or numbness/tingling. The pain may also extend from the lower back down the buttocks and one or both legs.
The lower back, also referred to as the lumbar section of the spine, comprises five bones – vertebrae – stacked on top of each other, with a disc of fibrocartilage (an 'intervertebral disc') between each one.
These discs act as a type of cushion to allow the back to bend and twist. Towards the back of each vertebra is an enclosed space called the spinal canal through which the spinal cord travels from the brain to the lower section of the body.
Major nerves radiate out from the spinal cord in the gaps between the vertebrae. Bony protrusions at the back of each vertebra called facet joints connect each vertebra to the one above and the one below and give stability to the spine.
Finally, a number of muscles and ligaments attach to the spine and control movement.
A lot of the time lower back pain is caused by strains of these muscles and ligaments (called myofascial pain), however other factors may cause pain too, such as a herniated disc or osteophytes ('bone spurs'), which may put pressure on the nerve roots where they come out from the spinal cord. The facet joints become major sources of pain with increasing age.
Lower back pain is classified into two types according to what is causing the pain…
- Mechanical lower back pain refers to pain resulting from inflammation caused by some form of injury or irritation to components of the back such as the facet joints, the discs, the ligaments or muscles or where one vertebra slips out of place (called spondylolisthesis). As well as physical injury, mechanical lower back pain can be caused by infections or tumours in or near the spine.
- Neuropathic lower back pain describes where a nerve root is being compressed or irritated (sometimes referred to as a 'pinched nerve') by a herniated disc or an osteophyte. Pain will often radiate from that section of the lower back down the leg/s (this is known as sciatica).
Because the spine is such a complex composite structure, correct diagnosis needs to be made by a doctor before any treatment is offered.
Most of the time, expensive imaging is not needed to make the diagnosis, but should be reserved for cases where the doctor suspects fracture, infection, tumour or significant structural abnormality.
Appropriate treatment will depend on the cause and severity of the pain.