Lower back pain

There are many things that can cause lower back pain. As a physio we first have to rule out red flags.

The main red flag we look out for is causal equina syndrome. Cauda equine means the horses tail and is used to describe the spinal cord terminating at the T12/L1 and then giving rise to the nerve root that descend to give sensory motor control to the lower limbs. Any insult about this level is considered an upper motor neurone lesion; anything below this level a lower motor neurone lesion.

Cauda equine syndrome is quite rare with 1 in 2000 cases of low back pain have compression on the spinal nerve roots. It is however a medical emergency that can lead to permanent bowel and bladder dysfunction.

If this is not identified properly and acted upon immediately with a referral to A and E the average laws suit pay out could be £336,000.

The consensus for CES is low back pain with or without leg pain with changes in bowel or bladder habits or a lack of sensation between the legs around the genitals and back passage.

However, CES presentation is highly variable and may present as follows:

• Low back pain
• Unilatral leg pain
• Bilateral leg pain
• Bladder retention or incontinence
• Bowel incontinence

Spinal cancer

Low back pain caused by cancer only accounts for 1% of cases, however we must screen for this as LBP is so prevalent. Unfortunately, there is insufficient evidence for red flag question accuracy in identifying spinal cancer.However, the following signs give us an idea that spinal cancer might be a concern:

• Weight loss – 5% of bodyweight in 4 week period is significant
• Constant unremitting night pain that affects the patient getting to sleep, causes waking at night and doesn’t subside if the patient changes position in bed
• Night fevers – indicate lymphoma and leukaemia
• Low back pain not improving with conservative management
• Previous cancer history with low back pain (there is a genetic link with breast cancer)
• Age of onset of first episode of low back pain < 20 and >50.

So if you haven’t got spinal cord compression (CES) or spinal cancer what can cause lower back pain?

Non-specific lower back pain

There are numerous causes of back pain including disc degeneration, facet joint compression, nerve root irritation, spinal fractures called spondylolisthesis, spinal stenosis etc…

The most common cause is natural age related wear and tear in the discs and joints, sometimes referred to as Non Specific Lower Back Pain (NSLBP). It may look like the MRI below.

You may experience a deep dull aching pain in the back with referred pain into the buttock. it is usually stiff and sore in the morning, with prolonged sitting and also with bending or exercise. Should you be worried if you have an MRI and it looks like this?

Not necessarily. Wear and tear in the spine is a natural ageing process. It starts as early as your 20’s and progresses through life sometimes causing back pain. Studies have shown that of people with no back pain at all – 50-60% of them have MRI that show pathology (disc bulges, joint compression etc…)

So do you wait until you have back pain until you see a physio?

Slipped discs?

Degenerative spinal discs. This looks and sounds scary, however very common, and not always something to lose sleep over. It’s a natural aging process. But, can cause back pain from time to time… The discs acts as shock absorbers between the bones and help to facilitate normal movement such as bending and twisting.

The discs themselves don’t always cause back pain as they don’t have much nerve supply, it’s the adjacent bones and joints that cause the deep dull aching and sometimes sharp shooting pain that you experience with an episode of back pain.

Trapped nerves?

Trapped nerve and sciatica are common terms with lower back pain. However the nerve doesn’t get trapped – or can become compressed, especially by a disc bulge but also by an enlarged facet joint or tight muscle, and then becomes inflamed. Compression on the nerve blocks the flow of information through the nerve leading to pins and needles, numbness or weakness. An inflamed nerve can be extremely painful, referring pain down the arm or leg in the distribution that the nerve supplies. Although this nerve irritation can be extremely painful it normally resolves with time and treatment (it can take several months to resolve)

Spondylolisthesis

This is a type of stress fracture in the spine that cause instability and back pain. They are graded 1-4, with 4 being the most severe type. 90% of the time they can be managed without surgery and improvements can be expected in 6- 12 weeks for grade 1 and 12 to 20 weeks for a grade 2. Core stability and pain management are the key concepts here