Low Back Pain

Low back (lumbosacral) pain accounts for at least 5% of general practice presentations; 85-90% of the population will experience back pain at some stage, and 70% of the world's population will have at least one disabling episode. At least 50% recover within 2 weeks and 90% within 6 weeks, but recurrences are frequent (reported in 40-70%) and 2-7% develop chronic pain. Most common in those aged 30-60 (average 45 years). A specific pathoanatomical cause can be identified in perhaps only 8-15% of acute presentations — the large majority is 'non-specific back pain', usually attributed to dysfunction of the facet joint, intervertebral joint/disc, or ligamentous/muscular attachments ('mechanical back pain').

• Pain pattern questions: general health, nature of pain, precipitating injury, worse on waking or later in the day, sleep quality, effect of rest, effect of activity, worse sitting or standing, effect of coughing/sneezing/straining
• Radiation: what happens to back/leg pain on a long walk (vascular vs neurogenic claudication)
• Associated features: psoriasis, diarrhoea, penile discharge, eye trouble, pain in other joints (spondyloarthropathy screen); urinary symptoms; medications including anticoagulants; psychosocial stress, mood
• Mechanical pattern: pain provoked by activity, relieved by rest; worse end of day/after activity; tends to be unilateral and diffuse; deep dull ache, sharp if root compression
• Inflammatory pattern: insidious onset; aching/throbbing; severe prolonged morning stiffness; worse with rest, relieved by activity; worse at night/early morning; more localised, may be bilateral or alternating
• Pain worse standing/walking, relieved by sitting suggests spondylolisthesis; pain worse sitting, better standing suggests a discogenic problem
• Calf pain travelling proximally with walking suggests vascular claudication; buttock pain descending with walking suggests neurogenic claudication (spinal canal stenosis)
• Yellow flag psychosocial risk factors for chronicity: abnormal illness behaviour, fear-avoidance beliefs, compensation issues, unsatisfactory restoration of activities, failure to return to work, unsatisfactory response to treatment, treatment refused, atypical presenting signs

• Inspection from the moment the patient is sighted — gait, how they rise from a chair, undress, mount the couch; a person who prefers to stand likely has a significant disc lesion
• Note lumbar lordosis, lateral deviation (functional scoliosis, usually away from the painful side), muscle wasting, midline moles/hair tufts/haemangioma (possible spina bifida occulta)
• Active movements: forward flexion, extension, lateral flexion L and R (normal ranges: flexion 75-90°, extension 20-30°, lateral flexion 30°)
• Palpation centrally (spinous processes to coccyx), unilaterally 1.5cm from midline, and transverse pressure to the sides of the spinous processes
• Straight leg raise (Lasègue) test — passive test, knee extended, ankle dorsiflexed; 20-60° elevation reproducing pain indicates dural irritation/sciatica
• Neurological exam if pain/paraesthesia/weakness extends into the leg: quick tests (walking on heels = L5, walking on toes = S1), dural stretch tests (slump test, SLR), specific nerve root tests (L3, L4, L5, S1 — motor, sensation, reflex)
• Rectal examination to check for flaccidity if cauda equina syndrome is suspected
• Examine related joints (hip, sacroiliac) and assess pelvis/lower limbs for deformity (e.g. leg length discrepancy)

Clinical features and diagnosis of vertebral dysfunction leading to low back and leg pain — symptoms/signs can occur singly or in combination.

Serious disorders not to be missed: ruptured or dissecting aortic aneurysm, retroperitoneal haemorrhage (especially on anticoagulants), neoplasia (myeloma, pancreatic carcinoma, metastases — the big three are lung/breast/prostate, others thyroid/kidney/adrenal/melanoma), severe infections (vertebral osteomyelitis, epidural abscess, septic discitis, tuberculosis, pelvic abscess/PID), osteoporotic compression fracture, and cauda equina compression. Commonly missed pitfalls: the spondyloarthropathies (ankylosing spondylitis, reactive arthritis, psoriatic arthropathy, inflammatory bowel disease), sacroiliac dysfunction, spondylolisthesis, vascular or neurogenic claudication, Paget disease, prostatitis, and endometriosis. Depression and urinary tract infection are important 'seven masquerades' to actively consider — UTI especially in a young or pregnant woman with upper lumbar pain, even without dysuria/frequency.

• None, for acute non-specific low back pain <6 weeks without red flags — Plain X-rays and MRI are not recommended here — limited diagnostic value and no benefit in physical function; strict adherence to imaging red flags still produces many false positives (e.g. night pain present in 44% of cases, <1% have serious pathology)
• Plain X-ray lumbar spine — In the presence of red flags — may exclude basic bony abnormalities (osteoporosis, malignancy), but majority of spinal X-rays/MRIs show incidental abnormalities with increasing age (disc bulges found in 70-90% of asymptomatic volunteers)
• FBE, ESR/CRP — Screening for chronic pain, especially with red flags present
• Serum alkaline phosphatase — Screening — Paget disease, bone turnover
• Urine dipstick — Screening — exclude UTI as a masquerading cause
• PSA — Males >45 years as part of chronic pain screening

• MRI — Most appropriate imaging where serious pathology is suspected (red flags present), or suspected myelopathy
• Serum electrophoresis, Bence-Jones protein — Suspected multiple myeloma
• Brucella agglutination test, blood culture — Suspected brucellosis / pyogenic infection / bacterial endocarditis
• Tuberculosis studies — Suspected TB, especially in at-risk migrant populations
• HLA-B27 — Suspected spondyloarthropathy
• Radionuclide (technetium) bone scan — Suspected neoplastic or metabolic disease, or infection before changes apparent on X-ray
• CT scan, myelography/radiculography, discography — Procedural/preprocedural tests reserved for undiagnosed red-flag disorders, especially before planned surgical intervention for disc prolapse

• The aim of treatment is to reduce pain, maintain function, and minimise disability, work absenteeism and the risk of chronicity
• Current evidence for acute low back pain: beneficial — advice to stay active and reassurance, NSAIDs; likely beneficial — analgesics and stretching; lacking firm evidence — spinal mobilisation/manipulation, back exercises, trigger point injections, acupuncture
• For chronic low back pain (>12 weeks): beneficial — back exercises, multidisciplinary treatment program; possible benefit — weight loss, analgesics, NSAIDs, trigger point injections, spinal mobilisation/manipulation
• Advice to stay active speeds symptomatic recovery, reduces chronic disability and results in less time off work than bed rest; encourage return to work as early as possible
• Non-specific back pain: if patients with uncomplicated back pain receive no treatment, one-third will get better within 1 week and by 3 weeks almost all the rest are better

• Acute: explanation and reassurance about no evidence of serious damage or disease; back education program; encouragement of normal daily activities including work; physical therapy — stretching of the affected segment, consider spinal mobilisation or manipulation if no contraindication; review in about 5 days; no investigation needed initially
• Heat (heat bags, hot flannels) is beneficial, especially in the first 2-4 weeks of acute low back pain — more effective than placebo for pain relief; evidence for cold application is equivocal
• An early graduated exercise program as the acute phase settles has reasonable supporting evidence; all forms (extension, flexion, isometric) appear roughly equally effective; walking and supervised swimming are also therapeutic
• Chronic: back education program and ongoing support; encouragement of normal activity; exercise program; mindfulness-based stress reduction (evidence-based); consider a multidisciplinary rehabilitation team or 'back school' (though evidence suggests only trivial improvement)
• For chronic non-specific low back pain, psychological interventions are most effective when delivered in conjunction with physiotherapy (mainly structured exercise)

Prevention of further back pain: education about back care including a good layperson's reference, golden rules for lifting/sitting/bending/sport, and a tailor-made ongoing exercise program.

1. 1. Non-drug measures first in all patients (education, staying active, heat, graduated exercise)
2. 2. Trial of paracetamol is reasonable given its safety profile, despite evidence it is generally ineffective for non-specific low back pain
3. 3. NSAIDs fare somewhat better than paracetamol in trials and are particularly useful where there is clinical evidence of inflammation, severe spondylosis, or acute radicular pain — use for a limited course (10-14 days) then cease and review
4. 4. Muscle relaxants can be added for short periods only, given sedation/neurological/addiction risks
5. 5. Opioids are not recommended as routine, but may be considered short-term for severe pain unrelieved by the above
6. 6. A short corticosteroid course can be considered for very severe acute sciatica
7. 7. For chronic back pain, consider antidepressants only if the patient is depressed, not as a routine analgesic measure

• Mechanical spinal dysfunction remains the most common cause of back pain in the elderly, and disc prolapse/facet joint injury can present surprisingly often even at advanced age
• Degenerative joint disease (lumbar spondylosis) is very common and, if advanced, can present as spinal canal stenosis with claudication and nerve root irritation from narrowed intervertebral foraminae
• Special problems to consider: malignant disease, degenerative spondylolisthesis, vertebral pathological (osteoporotic) fractures, and occlusive vascular disease

• Injection techniques: trigger point injection (limited evidence, local anaesthetic 5-8mL into tender points); facet joint corticosteroid injection under image intensification (best evidence does not support benefit); caudal (trans-sacral) epidural injection with local anaesthetic ± corticosteroid for persistent sciatica (0.25% bupivacaine 15mL) — Cochrane review found corticosteroid no better than placebo
• Physical therapy: active exercises are the best form; passive spinal stretching at end-range is safe and modestly effective; spinal mobilisation (gentle, repetitive, rhythmic movement) is safe and modestly effective; spinal manipulation (high-velocity thrust) may produce a faster response but evidence is conflicting and requires greater skill — in chronic low back pain, regular manipulation gives slight improvement at 1 month that disappears by 6 months; adverse effects are uncommon but can be serious
• Other treatments with limited/mixed evidence: hydrotherapy, TENS, therapeutic ultrasound, posterior nerve root (medial branch) blocks ± denervation, percutaneous vertebroplasty (for osteoporotic fracture), deep friction massage (with mobilisation/manipulation), acupuncture (no evidence acute, short-term relief chronic), biofeedback, lumbar supports (don't prevent pain, conflicting evidence on symptom relief), traction (little or no impact)
• Non-organic (psychogenic) back pain: like headache, back pain can be a symptom of an underlying functional/psychological disorder. Depressed patients are often less demonstrative than anxious/conversion-disorder patients, so the non-organic basis can be easy to overlook. Diffuse tenderness to light touch, atypical dermatomal distribution and disproportionate disability are clues. A validated tool such as the STarT Back screening tool (SBST) can quantify psychosocial risk (low/medium/high) to guide prognosis and treatment. A trial of antidepressants for a minimum of 3 weeks can be reasonable where relevant.
• Surgical intervention for radiculopathy — absolute indications: bladder/bowel control disturbance, perineal sensory change, progressive motor disturbance (e.g. significant foot drop, quadriceps weakness). Relative indications: severe prolonged/disabling pain; failure of conservative treatment with persistent pain; or all four of — leg pain ≥ back pain, positive SLR, no response to conservative therapy after 4-6 weeks, and imaging showing a lesion matching symptoms. A 10-year controlled study found surgery gave significant sciatica relief for 1-2 years versus conservative treatment, but outcomes (including neurological deficits) were equal by 10 years — surgery has a limited role.
• Thoracic back pain (upper/dorsal spine) is a related but distinct presentation, commonly from costovertebral joint dysfunction; pitfalls include cardiac causes (MI, dissecting aneurysm presenting as interscapular pain), pre-eruption herpes zoster, and penetrating duodenal ulcer or oesophageal spasm referring pain to the lower thoracic spine.

• Urgent: myelopathy, especially acute cauda equina compression syndrome (Syndrome A)
• Urgent: severe radiculopathy with progressive neurological deficit (Syndrome B)
• Urgent: spinal fracture
• Persistent pain or dysfunction not responding to conservative management — refer to a physiotherapist or exercise specialist
• Evidence or suspicion of a sinister cause (e.g. neoplasia, infective discitis/osteomyelitis in a child)
• Suspicion of cardiac or gastrointestinal referred (persistent) pain
• Significant adolescent scoliosis or kyphosis (e.g. Scheuermann disease)
• Sciatica/radiculopathy meeting surgical criteria (see Other considerations) — refer to a spinal surgeon
• Suspected spondyloarthropathy — refer for shared specialist care

• Explain the generally favourable natural history: about one-third of patients improve within 1 week even without treatment, and almost all the rest improve by 3 weeks; 50% recover within 2 weeks and 90% within 6 weeks — but recurrence is common (40-70%)
• Advise to stay active and keep moving despite discomfort — this speeds recovery more reliably than rest
• Clearly explain red flag symptoms that warrant urgent review: saddle anaesthesia, new bladder/bowel dysfunction, progressive leg weakness, fever, unexplained weight loss, pain unrelieved by rest or worse at night
• Review at about 5 days for acute presentations to reassess and consider physical therapy; review response to NSAIDs after 10-14 days and cease if not helping

• Back pain related to posture, aggravated by movement and sitting, relieved by lying down, suggests vertebral dysfunction, especially disc disruption
• Pain from most disc lesions is generally relieved by rest
• Plain X-rays are of limited use, especially in younger patients, and may appear normal even in disc prolapse
• Always consider depression as a cause or aggravator of back pain; if suspected, consider a trial of antidepressants
• If back pain persists, is possibly worse during bed rest at night, consider malignant disease, depressive illness or other systemic disease
• Pain worse on standing/walking, relieved by sitting, is probably spondylolisthesis
• Pain and stiffness present on waking and lasting >30 minutes suggests inflammation
• Avoid strong analgesics, especially opioids, in any chronic non-malignant pain state
• Bilateral back pain is more typical of systemic disease; unilateral pain typifies mechanical causes
• Back pain at rest with morning stiffness in a young person demands careful investigation for ankylosing spondylitis or reactive arthritis
• A disc lesion at L5-S1 can involve both L5 and S1 roots — but combined L5 and S1 root lesions should still raise suspicion of malignancy
• A large central disc protrusion can cause bladder symptoms — either incontinence or retention