Back Pain Assessment


Dr Cameron says:

I first wrote the following article about back pain assessment about ten years ago and it's been published several times online and in magazines since. It was written for the education of other doctors and therapists but I think there's a lot in it that will benefit anyone suffering from back pain or lower back ache.

You should see it as a guide to the steps a doctor takes when assessing lower back pain, the cause of lower back pain and in planning for back pain relief. I've written lots more about lower back pain treatment over at my other site on www.cameronmedical.com 


Case study

Elaine is a forty one year old secretary. She has had lower back pain several times previously and presents again with a similar episode. She seeks back pain relief! The back pain is to the left of her lumbar spine and radiates into her buttock and outer thigh. She denies numbness or pins and needles and her bowel and bladder control is normal. She wonders about attending an osteopath. You are unsure how to advise her and give her a prescription for diclofenac. This gives her dyspepsia and she stops taking it after ten days. A month later she still has grumbling discomfort but has not returned to consult you. She eventually attends a local private physiotherapist who manipulates her spine to great effect and her pain fully settles.


Lower back pain - except in the rarest of circumstances - is not life threatening. But it is common and many patients suffer greatly because of it. A busy family doctor won't think so but most people with back pain deal with it themselves. Thirty seven percent of adults in the UK experience lower back pain in any one-year period but only fourteen percent will seek medical help to obtain back pain relief. Of those who don't trouble their family doctor, many will self medicate, some will attend a physiotherapist and an increasingly large number will have spinal manipulation performed. Many family doctors feel inadequately trained to assess back pain. This causes uncertainty and leads to over-prescribing, unnecessary use of X-rays and needless referral to hospital specialists. Lower back pain patients are often best served by remaining at work but only a doctor confident in their assessment skills can push in that direction.



CLINICAL ASSESSMENT of Lower Back Pain

A good assessment can be obtained in the space of a ten-minute consultation – all you need is a reliable examination routine – I suggest something like the following:

Observe your patient

You can learn by watching your patient walk through the waiting room. Take note of their posture, their facial gestures and the way they walk. Assess their demeanour.The tendency to "somatize" inner unhappiness can lead to inconsistent or bizarre examination findings but be careful how you interpret them. Chronic back pain can be associated with psychosocial difficulties and many patients use it as a means of communicating distress. True malingering is extremely rare. Almost all patients have an underlying physical problem but, for some, their inner belief systems lead them to magnify the intensity and importance of their lower back pain.

Some chronic back pain sufferers respond to counselling or antidepressant medication. Learn to use your own feelings as a barometer for their psychological state! Patients who make their doctor feel depressed are probably depressed themselves!


Take a good history

  • What age are you Mr Smith?

Most patients consulting their GP with lower back pain are between the ages of twenty five and sixty. Back pain is rare in teenagers and not common as a new presentation in the elderly. If you meet a patient in either of these two categories then lower your threshold for investigation.

  • And what do you do?

Occupation is important. It gives a pointer towards prognosis but not in the way many would expect. Job satisfaction is crucial! Patients in heavy manual jobs do get more back pain than others but those who hate their jobs – whether senior executive or toilet cleaner - are much more likely to take time off.

Next, try to place this episode of back pain in its proper context. I often find it useful to review the patients past medical history and current use of medication before obtaining any other details. Ask the following (or review the case notes):

  • "Tell me about your general health and any previous health problems"

Have they had cancer? Tumours of the breast, lung, prostate, kidney and thyroid are particularly likely to metastasise to bone. Might they be HIV positive or could they have had TB? Always ask about symptoms of systemic ill health such as weight loss, night sweats or fatigue and remember that osteoporosis places the patient at risk of vertebral collapse

  • "Have you had previous surgery?"
  • "Have you had back pain before? How was it treated?"

Back pain is often a recurrent symptom and most patients first experience it in their twenties or thirties. Be wary of the elderly patient who presents with back pain for the first time ever (or the first time for a long time) – they may have serious underlying pathology! Previous experience of treatment will colour the patients expectation of what you, the GP, can or should provide. Many patients get very hung up on the labels applied to their condition by previous therapists and this can sometimes cause problems in communication. Take time to clarify what they mean by the words or phrases they use.

  • "Do any other joints give you trouble?"

Most lower back pain is not related to underlying disease but remember that it may be a manifestation of ankylosing spondylitis or rheumatoid arthritis.

  • "What medication are you taking?"

Is your patient being treated with anti-mitotic drugs such as tamoxifen? Steroid therapy – now or in the past – leaves them at risk of osteoporosis and vertebral collapse.

  • "Are you taking anything for the pain?"

The answer to this question sheds light on the patient's belief about the significance of the pain. Beware the patient who sees it as your job to "fix them." This abdication of responsibility for their own health puts them at risk of long term illness behaviour. Fear of what the pain might mean and subsequent avoidance of pain provoking activities are also bad prognostic factors.


The history proper

Onset and duration

Try to discover how long the pain has been present and how it started. Most patients can recall an event that triggered the problem and an approximate time of onset. Be wary of the pain that just seemed to creep up from nowhere – it may indicate serious pathology.

Site and spread of the pain

Is the pain mainly in the back or mainly in the leg? Mainly in the leg and associated with numbness or pins and needles points towards nerve root involvement. Nerve root pain is typically shooting, lancinating, or like an "electric shock" and may be felt all the way to the foot. Most simple back pain does not spread far beyond the buttock, is dull in nature, and patients say it feels like toothache. Take care over descriptions of the site of pain – many people say "hip" when they mean "buttock."

Behaviour of the pain

Beware the patient who can never get comfortable! No matter what is wrong with their back, your patient will always find a position that gives them some relief. The only exception is when serious pathology is present. Chronic, unremitting pain – particularly if sleep is disturbed – is in my view the most immediately alarming "red flag" in any pain history.

Most cases of back pain get better with rest and worse with activity. The exception is in ankylosing spondylitis when the opposite is true!

Other important questions

A patient with cauda equina compression will describe loss of sphincter control and may have bilateral neurogenic type leg pain. Test for impaired sensation in the saddle area and assess anal sphincter tone by digital examination while the patient tries to "squeeze" your examining finger. A compressed nerve root recovers in time but a compressed cauda equina never does and the patient risks being left permanently incontinent of urine and faeces. The condition is rare but all GP's should be alert to the possibility. If in any doubt – admit the patient to hospital immediately.





EXAMINATION

The physical examination of the patient with back pain should follow a logical thought process and with practice takes no more than a few minutes. The bad news for GP's is – you need to undress the patient! This is often the most time consuming part of the process but the extra information gained makes the exercise well worthwhile.


With the patient standing:

  • Inspect for obvious spinal asymmetryAssess the lumbar lordosis – a very flat lordosis may point towards ankylosing spondylitisLook for muscle wasting in the gluteal region, the calf or the thighCheck for discrepancy in leg lengths by comparing the levels of knee and buttock creases and the relative levels of the posterior superior iliac spines.
  • Ask the patient to extend their spine, to flex forward and then to side flex by sliding their palms down their outer thigh. This assesses quality and range of spinal movement. Most patients with simple back ache will be slightly stiff in extension, be painful on flexion and show asymmetric limitation and pain on side flexion of the spine.

Lie your patient flat and supine:

Rule out other joint involvement

  • check the hip joints for range of movement and for pain or limitation. Hip joint pathology can present with predominant back and buttock pain although more typically a "hip patient" will feel pain in the groin. A loss of range on internal rotation of the hip is often the earliest sign of hip disease.
  • Perform stress tests on the sacroiliac joints – especially in younger or female patients. Mechanical dysfunction or inflammatory processes in these joints produces buttock and groin pain which may radiate down the leg.

Test the nerve roots

  • Straight leg raise test. This stretches nerve roots L5, S1 and S2. Pick up the leg at the ankle and keep the knee fully extended. Take the leg up towards ninety degrees or beyond. If the patient has significant nerve root entrapment then you will reproduce their shooting leg pain before you get much beyond thirty degrees of elevation. Back pain produced by straight leg raising is common and does not indicate nerve root involvement.
  • Assess muscle power and tone – see box
    • Check the reflexes. The knee jerk is innervated from the L3 and L4 nerve roots, the ankle jerk from L5 and S1Assess the babinski plantar response
    • Check for skin sensory loss

    Turn your patient over into prone lying

    • Femoral nerve stretch test (nerve roots L2, L3 and L4). Keep the patients anterior thigh fixed on the couch and flex the knee towards ninety degrees. If they have femoral nerve irritation or entrapment then this manoeuvre will produce burning discomfort in the groin and anterior thigh.
    • Palpate the spine for tenderness and for muscle spasm

    With practice you can perform the above examination in no more time than it took you to read about it. By the end of the process you will have differentiated between patients with simple backache (the vast majority), with nerve root pain (a few) and with possible serious spinal pathology (as rare as "hens teeth!") and can now plan a course of treatment.

     



FURTHER INVESTIGATION

Most patients with back pain need no investigations performed before starting treatment. X- rays are over used and rarely help plan management. The royal college of radiologists state that one set of lumbar films uses the same amount of radiation as a hundred and fifty chest X-rays. False positive findings abound and often only confuse the issue. The RCGP guidelines suggest X-raying if the pain has been present for more than six weeks but I find in practice that even at that stage the result rarely contributes much to the management decision process.X-rays are of benefit in the younger patient with back pain when spondylolysis or spondylolisthesis are possible diagnoses. They may also help in detecting osteoporotic collapse in the elderly and you may wish to use them if the patient has had recent trauma, whatever their age.

Do not use plain X-ray if you suspect serious pathology. Even advanced tumour may not show on the films. If you suspect underlying disease then check bloods for a full blood count, an ESR and an alkaline phosphatase level (with isoenzymes for bone if the basic level is elevated). Arrange an isotope bone scan - many areas of the UK now allow GP's direct access to radioisotope imaging in these circumstances.


The role of MRI scanning

Magnetic resonance imaging is an amazing technology and has advanced our understanding of back pain. But it is not the gold standard some see it to be and shares many draw backs with simple X-ray.False positive results are common and the scan picture does not always correspond to the patient's clinical presentation. MRI can be entirely normal in people with severe back pain and patients who have never had back pain in their lives can show marked changes on scanning.In my view it is best to make a diagnosis based on a good history and clinical examination. MRI is not usually appropriate for patients with predominant back pain and is best reserved for the investigation of neurogenic leg pain or as an alternative to isotope bone scan in cases of possible serious pathology. In some senses it is best seen as a "route map" for the surgeon.

Many specialists in the field now acknowledge that society and the medical profession have colluded to produce an epidemic of back pain. But at last the focus is moving away from highly technical and hugely expensive procedures towards the sort of simple interventions that may transform the lives of most that are afflicted. Back pain rarely kills patients but, if mishandled, can lead to loss of earnings, the break up of marriages and a lifetime of misery. The assessment of back pain is not difficult to learn but for now our report card reads "trying hard …. but must do better!"


Other useful pages:

Neck pain treatment

Carpal tunnel injection

Neck and shoulder pain

Copyright: 2010.
Doctor Cameron is a specialist in joint pain, sports injury and joint injection treatments.