Low Back Pain and Sciatica

Low back pain is an extremely common problem that is often poorly managed. Back pain is a particular challenge because it is so common, demanding of medical resources and a major cause of physical, psychological and social disability. Most back pain is simple and self-limiting but it is important to recognise that which is not.

See related articles: Examination of the Spine, Lumbar Spinal Stenosis and Back Pain in Children.

The aims of back pain assessment are:¹

• To recognise serious pathology.
• To relieve pain.
• To improve function.
• To recognise and assess level of disability.
• To identify barriers to recovery.
• To prevent recurrence or persistence of symptoms.

• Most backache (85-90%) will be so-called simple low back pain (or 'mechanical low back pain') in which the symptoms by definition cannot be ascribed to a particular pathology (infection, tumour, osteoporosis, fracture, radicular syndrome, cauda equina syndrome (CES)). Simple low back ache is also called uncomplicated or non-specific low back pain and will vary with posture, activity, time and treatment.
• Radicular (or nerve root pain) may occur with low back pain. Sciatica is a lay term for pain extending into the leg (buttock, thigh, calf or heel).
• The classification into acute (less than 6 weeks), sub-acute (6-12 weeks) and chronic (more than 12 weeks) has been used in research but is less useful clinically because of the variable and recurrent nature of symptoms.
• Recurrent low back pain has been defined as a new episode of pain after a symptom-free period of 6 months.¹

• Back pain is extremely common, affecting 80%-90% of adult men and women between the ages of 30 and 50 years.
• 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.
• Back pain is second only to the common cold as a cause of lost days at work. In 2005, the Trades Union Congress (TUC) estimated that 4.9 million working days per year are lost due to back pain.³ The TUC also found that there was a demographic change in sufferers from manual labourers to those who work in offices³. 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.
• Both high physical workload and job dissatisfaction increase the risk of absence due to back pain.⁴ Psychological factors are important.⁵ Smoking and obesity increase risk.⁶

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.

This is described in more detail in the Back Examination article.

• A brief examination for acute back pain is recommended with the patient undressed, revealing spine, and standing.
• The brief examination should incorporate: inspection, palpation, brief neurological examination and an assessment of function.
• More detailed neurological examination will be necessary if the history suggests any red flags, e.g. confirming saddle anaesthesia and diminished anal tone if CES is suspected.
• Passive straight leg raising is often used to assist diagnosis of nerve root pain but it is highly sensitive (90%) and not very specific (20%).⁷

Red flags may suggest spinal fracture, cancer, infection or serious pathology associated with prolapsed intervertebral disc.
Other causes of back pain include:

• Primary malignancy:
  • Reticulo-endothelial system (myeloma is the most likely)
  • Carcinoma of pancreas
  • Osteosarcoma (does not usually affect the spine)
• Secondary cancers are usually from:
  • Bronchus
  • Breast
  • Prostate
  • Thyroid
  • Kidney
• Bone disorders including:
  • Paget's disease of bone (affects the pelvis in 72% of cases and the lumbar spine in 58%)
  • Osteoporosis (leading to vertebral collapse)
  • Spinal stenosis
• Inflammatory disease, for example:
  • Ankylosing spondylitis (AS) which tends to present:
    • Slowly in men under age 40
    • With a rigid back
    • With aggravation by inactivity and relief with exercise
  • Psoriatic arthritis (rash or family history of psoriasis)
  • Reiter's syndrome (symptoms including urethritis)
  • Arthritis associated with inflammatory bowel disease (usually arthritis is peripheral)
• Infection:
  • Never forget tuberculosis (osteomyelitis can occur)
  • HIV predisposes to infections (including tuberculosis)
  • Renal tract infection (pyelonephritis can also cause referred back pain)
• 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

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.⁸ Consideration of these associations can reduce the number of fruitless back X-rays without missing malignancy.

• Note: 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.

Diagnostic imaging

This is indicated only if serious or specific pathology is likely, e.g. red flags:^9,10

• Plain X-ray of the lumbar spine:
  • Provides the same dose of radiation as around 120 chest X-rays and, in return, offers very limited information and rarely affects management.
  • Should not be used routinely.¹¹ That is not to suggest that there is no place for it:
    • If fracture is suspected, X-ray is of value.
    • With metastatic carcinoma.Those from prostate are sclerotic, those from lung, thyroid and kidney are osteolytic and those from breast may be either. Lesions below 2 cms in diameter may not be seen on plain X-ray but a scintillation scan with ^99mTc is much more sensitive.
    • Collapse from osteoporosis or myeloma may be seen.
    • Paget's disease of bone may be seen.
• CT scans often show stress fractures and spondylolisthesis best.
• MRI:
  • Gives a good picture of soft tissues, including discs and anything impinging on nerves or spinal cord.
  • Disc lesions are best displayed by MRI scans. MRI is the most useful investigation in nerve root compression, discitis and suspected neoplastic disease.^9,10

Blood and urine tests

• Full blood count, ESR, CRP, urine analysis if cancer, infection or inflammation suspected.^9,10
• LFTs may be helpful. Alkaline phosphatase can be elevated in metastatic disease and Paget's disease of bone.
• PSA will be raised particularly in carcinoma of the prostate.
• Urinary hydroxyproline will be markedly elevated (with increased bone turnover) in Paget's disease of bone.
• Nephrolithiasis may produce red cells in the urine.

Other investigations

A wide variety of further investigations may be required when other pathologies are suspected. For example:

• CXR may show primary or secondary carcinoma or pulmonary tuberculosis.
• Ultrasound will show renal stones and is the best way to visualise the pancreas. It can also give a good picture of an aneurysm allowing it to be measured accurately and to detect possible dissection.
• Endoscopy may confirm a posterior ulcer and allow tests for Helicobacter pylori infection or malignancy.

In 1994 the CSAG published a report that radically changed teaching and practice.¹² Until then, rest - perhaps with a board under the bed - was recommended for back pain. The new guidelines recommended active rehabilitation. The new principles of management involve keeping the patient active and giving analgesia to facilitate this. Now only in exceptional cases is rest allowed and then for no longer than 48 hours.

Management of simple low back pain

• Give information, reassurance and advice.
• DO NOT prescribe bed rest.
• Advise to stay as active as possible.
• Prescribe regular pain relief (paracetamol, non-steroidal anti-inflammatory drugs) and consider a short course of muscle relaxants.
• Referral:
  • Consider physical treatments, manipulation or multidisciplinary approaches if not resuming normal activities or if off work.
  • It is now recommended that such referrals be considered earlier than previously recommended; that is, 'after a week or two' (see Referral guidance recommendations below).
  • Multidisciplinary approaches include, for example, cognitive behavioural programmes and back schools.^5,13

Management of suspected serious pathology or red flags

If a red flag has shown, appropriate action must be taken. This will mean referral for investigation and for treatment. In the case of CES, for example, urgent referral to a neurosurgeon or specialist orthopaedic surgeon is required.

Management of chronic pain, psychosocial factors and yellow flags

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 psychosocial barriers to active rehabilitation with prolongation and chronicity as risks. These are called yellow flags. They include:¹⁴

• 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 and 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.

Identifying the 'yellow flags' should assist management. Evidence for interventions that work to change behaviour or prevent chronic pain and/or disability is thin.¹⁵
However if any 'yellow flags' are present they should be challenged and the patient offered a positive approach to active rehabilitation.
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, 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.¹⁶

Referral guidance^9,10

Remember when assessing whether to refer that motor deficits and bowel or bladder disturbances are more reliable than sensory signs.

• If red flags suggest a serious condition, refer with appropriate urgency. This means immediately for CES.
• If there is progressive, persistent or severe neurological deficit, refer for neurosurgical or orthopaedic assessment, preferably to be seen within 1 week.
• If pain or disability remain problematic for more than a week or two, consider early referral for physiotherapy or other physical therapy.
• If, after 6 weeks, sciatica is still disabling and distressing, refer for neurosurgical or orthopaedic assessment, preferably to be seen within 3 weeks.
• If pain or disability continue to be a problem despite appropriate pharmacotherapy and physical therapy, consider referral to a multidisciplinary back pain service or a chronic pain clinic.

Physical, cognitive and behavioural therapies

The evidence base for the value of physiotherapy, manipulation and acupuncture is poor.^17,18 Even the methodology of systematic reviews has been criticised as inadequate.¹⁹ 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. Traction is not recommended.²⁰

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.¹³ There may also be benefit from "back schools"²¹ and from exercise therapy.²²

Evidence for interventions that work to change behaviour or prevent chronic pain and/or disability is thin.¹⁵ There is evidence to show that behavioural treatments may work as well as exercise therapy¹³ and that 'back schools' for chronic and recurrent low back pain may be most effective at getting people back to work, but may not be cost-effective.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.²³
• Failure to diagnose CES and to take immediate action may lead to long-term neurological damage.
  Other sinister causes of back pain may have a fatal outcome. The prognosis may be improved by early and effective intervention.

This will depend entirely on the diagnosis.
Generally for simple low back pain, 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 it is most important to stay active.

For acute low back pain:²⁴

• Pain reduces rapidly for most within 1 month
• 75% of people return to work within 1 month
• 75% of people risk recurrence within 12 months (25% within 3 months)

If there is not a good response to management within 4 to 6 weeks, referral for further investigation and treatment should be undertaken.^9,10

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 HSE 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 back pain 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.

1. European guidelines for the management of acute nonspecific low back pain in primary care, COST B13 Working Group (2004)
2. Bandolier; Back Pain; September 1995
3. Trades Union Congress; Back Strain; 2005. Links to several related topics
4. Hoogendoorn WE, Bongers PM, de Vet HC, et al; High physical work load and low job satisfaction increase the risk of sickness absence due to low back pain: results of a prospective cohort study. Occup Environ Med. 2002 May;59(5):323-8. [abstract]
5. Linton SJ; Occupational psychological factors increase the risk for back pain: a systematic review. J Occup Rehabil. 2001 Mar;11(1):53-66. [abstract]
6. Deyo RA, Bass JE; Lifestyle and low-back pain. The influence of smoking and obesity. Spine. 1989 May;14(5):501-6. [abstract]
7. Deville WL, van der Windt DA, Dzaferagic A, et al; The test of Lasegue: systematic review of the accuracy in diagnosing herniated discs. Spine. 2000 May 1;25(9):1140-7. [abstract]
8. Deyo RA, Diehl AK; Cancer as a cause of back pain: frequency, clinical presentation, and diagnostic strategies. J Gen Intern Med. 1988 May-Jun;3(3):230-8. [abstract]
9. Back pain - low (without radiculopathy), Clinical Knowledge Summaries (November 2009)
10. Sciatica (lumbar radiculopathy), Clinical Knowledge Summaries (November 2009)
11. Kendrick D, Fielding K, Bentley E, et al; Radiography of the lumbar spine in primary care patients with low back pain: randomised controlled trial. BMJ. 2001 Feb 17;322(7283):400-5. [abstract]
12. Back Pain. Report of a CSAG Committee on Back Pain.; 1994 HMSO. ISBN 0-11-321887-7.
13. Ostelo RW, van Tulder MW, Vlaeyen JW, et al; Behavioural treatment for chronic low-back pain. Cochrane Database Syst Rev. 2005 Jan 25;(1):CD002014. [abstract]
14. New Zealand Guidelines Group; New Zealand Acute Low Back Pain Guide.; Includes the guide to assessing psycho-social yellow flags
15. van den Heuvel SG, Ariens GA, Boshuizen HC, et al; Prognostic factors related to recurrent low-back pain and sickness absence.; Scand J Work Environ Health. 2004 Dec;30(6):459-67. [abstract]
16. Hoogendoorn WE, van Poppel MN, Bongers PM, et al; Systematic review of psychosocial factors at work and private life as risk factors for back pain. Spine. 2000 Aug 15;25(16):2114-25. [abstract]
17. Smith D, McMurray N, Disler P; Early intervention for acute back injury: can we finally develop an evidence-based approach?; Clin Rehabil. 2002 Feb;16(1):1-11. [abstract]
18. Cherkin DC, Sherman KJ, Deyo RA, et al; A review of the evidence for the effectiveness, safety, and cost of acupuncture, massage therapy, and spinal manipulation for back pain.; Ann Intern Med. 2003 Jun 3;138(11):898-906. [abstract]
19. van Tulder M, Furlan A, Bombardier C, et al; Updated method guidelines for systematic reviews in the cochrane collaboration back review group. Spine. 2003 Jun 15;28(12):1290-9. [abstract]
20. Clarke J, van Tulder M, Blomberg S, et al; Traction for low back pain with or without sciatica: an updated systematic review within the framework of the Cochrane collaboration.; Spine. 2006 Jun 15;31(14):1591-9. [abstract]
21. Heymans MW, van Tulder MW, Esmail R, et al; Back schools for non-specific low-back pain. Cochrane Database Syst Rev. 2004 Oct 18;(4):CD000261. [abstract]
22. Hayden JA, van Tulder MW, Malmivaara A, et al; Exercise therapy for treatment of non-specific low back pain.; Cochrane Database Syst Rev. 2005 Jul 20;(3):CD000335. [abstract]
23. Linton SJ; A review of psychological risk factors in back and neck pain.; Spine. 2000 May 1;25(9):1148-56. [abstract]
24. Pengel LH, Herbert RD, Maher CG, et al; Acute low back pain: systematic review of its prognosis. BMJ. 2003 Aug 9;327(7410):323. [abstract]

• European guidelines for the management of acute nonspecific low back pain in primary care, COST B13 Working Group (2004)
• Trades Union Congress; Back Strain; 2005. Links to several related topics
• Health & Safety Executive; Back Pain in the Workplace