Assessment and Management of Low Back Pain

Low back pain is an extremely common problem that is often poorly managed. Most back pain is simple and self-limiting but it is important to recognise that which is not.

Related articles include:

• Sinister causes of back pain
• Acute spinal cord compression
• Back pain-non-sinister causes
• Back pain in children
• Spinal Disc Problems (including Red Flags Signs)
• Cervical disc protrusions and lesions

The basics of management include:

• Recognition of those causes of back pain that are a cause for concern and taking appropriate action (red flags)
• Planning a simple route for recovery with the patient, being positive and reassuring
• Recognising and addressing any factors that may mitigate against a swift recovery including negative attitudes and even compensation neurosis (yellow flags)
• Relief of pain
• Addressing issues that may predispose to further episodes, including poor practice at work or poor ergonomics

In 1994 the Clinical Standards Advisory Group (CSAG) published a report on back pain that almost completely inverted current teaching and practice.¹ Until then, advice had been to rest, perhaps with a board under the bed or directly on a board, and just lying flat was the basis of management. These new guidelines advised that only in exceptional cases is rest allowed and then for no longer than 48 hours. The principles of management were changed to keeping the patient active, giving analgesia as necessary to facilitate this. Active rehabilitation is the term to use.

• Simple back pain tends to affect those between 30 and 60 years of age, starting between 30 and 50. First onset outside this range should arouse suspicion of a sinister cause.
• Women tend to be off work with back pain more often than men but men tend to have longer periods off. This may be because men tend to do more heavy jobs.
• In 1995 Bandolier² reviewed the CSAG advice¹ and an epidemiological review,³ also from 1994.
• Despite the activities of the Health and Safety Executive, they found that the number of days of work lost each year due to back pain was rising.²
• In 2005, the TUC estimated that 4.9 million working days per year are lost due to back pain.⁴
• The TUC also found that there was a demographic change in sufferers from manual labourers to those who work in offices⁴.
• Both high physical workload and job dissatisfaction increase the risk of absence due to back pain.⁵ Psychological factors are important.⁶
• Smoking and obesity increase risk.⁷

History should include:

• When did the pain start?
• Was it sudden or gradual in onset?
• Where is it?
• Does it radiate anywhere else?
• Are there any aggravating or relieving factors?
• Has the patient had this problem before?
• Ask about occupation, what it involves and hobbies or sport.
• What does the patient think caused the pain?
• Note past medical history. Steroid use predisposes to osteoporosis. Has there been malignancy that metastasises to bone (lung, breast, prostate, thyroid, kidney) or myeloma?
• How has the patient been managing the condition? This includes analgesics taken, whether they have been adequate and attitude to the condition.

With the patient appropriately disrobed, examine the following:

• Look at the back.
  • Is there muscle spasm? This may be palpated more easily than seen.
  • Is there scoliosis, possibly due to spasm?
  • Is there loss of the normal lumbar lordosis?
  • There may also be erythema ab igne if heat has been injudiciously applied and the patient should be warned.
• Ask the patient to bend forward.
  • How far can he go?
  • Does he rotate to one side as he bends?
• Ask him to bend laterally to left and right. Is it symmetrical?
• Ask him to lie on the couch on his back.
• Straight leg raising is assessed by using the left hand to hold the knee in extension and placing the right hand under the heel to elevate it. Note how far it can reasonably be raised. Feeling resistance and looking at the patient's face makes it unnecessary to ask when it hurts.
• Where does is hurt? It may be in the back or resistance may simply be tight hamstrings in a stiff and unfit person.
• Repeat with the other leg.
• Collapse the head support of the couch and ask the patient to roll over on to his front.
• Femoral nerve stretch is elicited by bending the knee and noting how far it will flex. If there is pain, ask where. It may be in the thigh or from an osteoarthritic knee.
• Repeat on the other side.
• Use the triquitral of the right hand with the left hand on top of it to elicit springing pain along the lumbar spine and also the sacro-iliac joints.
• If the pain is severe, also elicit the knee and ankle reflexes as described in neurological examination of the lower limb. In most cases this can be omitted. In the elderly, the absence of ankle jerks does not necessarily imply pathology.⁸

The ability of this examination to diagnose prolapsed intervertebral disc is distinctly limited,⁹ but most of such lesions will recover with energetic conservative measures and do not require surgery.¹⁰

The most important aspect of differential diagnosis is the exclusion of serious warning signs called red flags. If they are present, appropriate action must be taken. Red flags may suggest spinal fracture, cancer, infection or serious pathology associated with prolapsed intervertebral disc.

• Primary malignancy of the reticulo-endothelial system of which myeloma is the most likely
• Carcinoma of pancreas
• Osteosarcoma does not usually affect the spine
• Secondary cancers usually from bronchus, breast, prostate, thyroid or kidney
• Metabolic disease of bone including Paget's disease and osteoporosis leading to vertebral collapse
• Paget's Disease affects the pelvis in 72% of cases and the lumbar spine in 58%
• Inflammatory disease. Ankylosing spondylitis tends to present slowly in men under 40. The back is very rigid. The condition is very much aggravated by inactivity and helped by exercise. There may be a positive family history, rash of psoriasis, urethritis, peripheral arthritis or inflammatory bowel disease.
• Infection. Never forget tuberculosis. Osteomyelitis can occur
• Causes from outside the spinal column include:
  • Dissecting aortic aneurysm
  • A posterior duodenal ulcer presenting as back pain may be difficult to diagnose. If a gastric ulcer presents for the first time over the age of 40, malignancy needs to be excluded.
  • Nephrolithiasis
  • Pyelonephritis can also cause referred back pain.
  • HIV infection predisposes to infections including tuberculosis.

Factors suggesting malignancy include age greater than or equal to 50 years, previous history of cancer, duration of pain greater than 1 month, failure to improve with conservative therapy, elevated ESR and anaemia.¹¹ Consideration of these associations can reduce the number of fruitless back x-rays without missing malignancy.

• If the diagnosis would appear to be simple back pain, then no investigation is required.
• If other diagnoses are entertained, appropriate investigations are in order, depending upon the suspicion.
• Plain x-ray or the lumbar spine provides the same dose of radiation as around 120 chest x-rays and in return it offers very limited information and rarely affects management. Therefore it should not be used routinely.¹² That is not to suggest that there is no place for it.
• If fracture is suspected, x-ray is of value and metastatic carcinoma or collapse from osteoporosis or myeloma may be seen. It should not be used routinely but in selected cases.
• Stress fractures and spondylolisthesis may be shown best by CT scan.
• Disc lesions are best displayed by MRI scans.
• Infectious or inflammatory disease may be indicated by blood tests such as FBC and ESR.

If a red flag has shown, appropriate action must be taken. In the case of cauda equina syndrome that means referral to a neurosurgeon or orthopaedic surgeon with an interest in backs that same day.

Most cases will be simple back pain and a positive and reassuring note is indicated. Talk to the patient. Explain that it is important to keep moving and to strive for a return to activity. Bed rest has been banned since 1994. Analgesics are appropriate for pain and should be used as required. Find something appropriate either on prescription or OTC.

Patients may, quite reasonably, assume that pain is a warning sign that tells us that if something hurts we should not do it. Very often this is true but with back pain it is necessary to work through the pain and to overcome it. There may well be psycho-social barriers to active rehabilitation with prolongation and chronicity as risks. These are called yellow flags. They include:¹³

• Belief that pain and activity are harmful
• Sickness behaviours such as extended rest
• Social withdrawal
• Emotional problems such as low or negative mood, depression, anxiety, stress
• Problems and/or dissatisfaction at work
• Problems with claims or compensation or time off work
• Overprotective family; lack of support
• Inappropriate expectations of treatment, including low expectations of active participation in treatment.

If any of these are found to be present they should be challenged and the patient brought into a positive approach to active rehabilitation. A defeatist approach is self-fulfilling.

Discuss work and predisposing factors for back pain.

• If heavy lifting is involved, was there an induction course when techniques were taught?
• Often it is not so much the weight but a large, awkward package that causes injury.
• Seating and posture are often more important nowadays.
  • Consider desks, chairs and computer screens and keyboards at work.
  • Look at time spent in the car and how comfortable it is and adjustment of the seat and steering wheel.
  • Fork lift trucks and large goods vehicles may transmit vibration all day.
• Discuss getting back to work.
• Discuss what improvements may be made to the workplace to reduce the risk of recurrence.
• Give the patient a positive attitude and enthusiasm to recover.

Not everyone finds that those in authority at work are sympathetic or wish to make the environment safer, but where work is supportive, the prognosis is better.¹⁴

Physical Therapies

The evidence base for the value of physiotherapy, manipulation and acupuncture is poor.^15,16 Even the methodology of systematic reviews has been criticized as inadequate.¹⁷ That is not the same as suggesting that there is evidence of lack of efficacy. Manipulation and acupuncture are each discussed in their own articles. The evidence base for all three in relation to the management of back pain is discussed in "Back pain non-sinister causes". Traction is not recommended.¹⁸

It is important to be active and positive to prevent back pain from becoming chronic. If it does, cognitive and behavioural therapy with relaxation therapy may be helpful.¹⁹ There may also be benefit from "back schools"²⁰ and from exercise therapy.²¹

Acute back pain may become chronic. This may be because of failure of active management or behaviour by the patient that predisposes to chronicity rather than cure. The yellow flag features have been well described but there is, as yet, little good evidence as to how to manage them. It would seem that such people must be encouraged or cajoled into taking part in an active process of rehabilitation. Psychological aspects are important in the transition from acute to chronic status.²²

If chronicity can be prevented, then recovery should be full but in a variable time. Back pain in old age probably is, as many assume, simply a feature of advancing years. Analgesics may help but the most important aspect is to stay active.

According to the Clinical Knowledge Summaries guidelines, about 75% of people who are off work are able to return within 4 weeks.²³ The risk of recurrence is about 25% within 3 months and about 75% with 12 months. They recommend that if there is not a good response to management within 4 to 6 weeks that referral for further investigation and treatment should be undertaken.

Over the past 40 years there have been far fewer jobs that involve heavy manual labour. Mechanical lifting devices are more often used. Almost anyone whose job involves lifting has an induction programme to teach safe lifting and the Health and Safety Executive has advice on the subject. Hence it is surprising that the figures from Bandolier² should show a rise rather than a fall in the incidence of back pain. They suggest that the change is due to changing attitudes and expectations rather than to pathology. It may be that there is a demographic move from back pain affecting manual labourers to affecting office workers as suggested by the TUC.

To a considerable extent, back pain is a preventable condition and safe practice with regard to lifting should be able to prevent much. There are European Guidelines for the prevention of low back pain.