Low Back Pain and Sciatica: Assessment, Red Flags and Evidence-Informed Management

1. First decide whether this is a routine MSK presentation

Most episodes of low-back pain are not caused by dangerous pathology. The first job is therefore not to identify the exact painful spinal structure; it is to decide whether the presentation fits common mechanical or radicular pain, or whether features suggest infection, fracture, cancer, inflammatory disease or serious neurological compromise.

This triage decision changes everything: a routine rehabilitation plan is appropriate only after important red flags have been considered in context.

2. Sciatica is a symptom pattern, not an imaging diagnosis

Sciatica usually refers to leg pain related to irritation or compromise of a lumbosacral nerve root. Symptoms may include radiating pain, paraesthesia, sensory change, weakness or altered reflexes.

The clinical picture should be built from symptom distribution and neurological examination. Imaging findings such as disc bulges are common and should not automatically be assumed to explain the patient's symptoms.

3. Red flags that need urgent thinking

• New bladder or bowel dysfunction with back/leg symptoms.
• New saddle or perineal sensory disturbance.
• Rapidly progressive or severe neurological weakness.
• Major trauma or fracture risk, including bone fragility.
• History or features raising concern for malignancy, infection or systemic disease.
• Constitutional illness, fever or unexplained deterioration when clinically relevant.

4. Cauda equina pattern: do not manage as routine physiotherapy

The combination of severe low-back or leg symptoms with new bladder, bowel or sexual dysfunction and/or perineal numbness requires immediate assessment through an appropriate emergency pathway. The physiotherapist's role is recognition and escalation, not trialling a routine exercise programme first.

5. Neurological examination

• Myotomal strength relevant to the suspected nerve root.
• Dermatomal or clinically meaningful sensory testing.
• Reflexes where appropriate.
• Neural mechanosensitivity tests interpreted alongside the rest of the examination.
• Walking, heel/toe function and functional weakness.
• Change over time: stable mild deficit is different from rapidly progressive weakness.

6. Imaging: ask whether the result will change management

NICE advises against routine imaging in non-specialist settings for low-back pain with or without sciatica. Imaging is more useful when serious pathology is suspected or when a specialist decision depends on the result.

A scan can identify anatomy, but it does not replace clinical reasoning. The key question is not 'Can we see a disc change?' but 'Does the imaging finding fit the symptoms and alter the treatment pathway?'

7. Self-management and activity

Education should support continued normal activity as far as possible, reduce unnecessary fear and explain the expected course. Prolonged avoidance can contribute to deconditioning and loss of confidence.

Exercise should be selected according to the person's needs, preferences and capabilities rather than because one universal exercise is believed to 'put the disc back'.

8. Manual therapy: an adjunct, not the entire plan

NICE allows manual therapy as part of a package that includes exercise, with or without a psychological approach. That wording is important: passive treatment should not replace active rehabilitation, education and restoration of function.

9. Psychosocial obstacles can change recovery

Fear of movement, low confidence, catastrophizing, work concerns and previous failed treatment can influence disability and recovery. These factors do not make the pain imaginary; they are part of the clinical context and may justify a combined physical and psychologically informed rehabilitation approach.

10. Clinical reasoning example

A patient with unilateral leg pain, reduced ankle reflex and sensory change that fit a nerve-root pattern but no progressive weakness or bladder/bowel symptoms may be managed conservatively with education, activity and individualized exercise while monitoring neurological status.

A second patient with similar pain but new urinary difficulty and saddle numbness belongs on an urgent referral pathway. The leg-pain label is the same, but the management is completely different because the risk profile is different.

11. Common mistakes

• Ordering imaging simply because pain is severe.
• Using one positive neural tension test as the diagnosis.
• Ignoring progression of weakness.
• Giving bed rest or excessive activity restriction without a clear reason.
• Using passive treatment indefinitely without functional progression.
• Missing psychosocial barriers that are maintaining disability.

Clinical takeaway

Good spine care begins with triage, then neurological and functional reasoning, then an active management plan. The therapist should know what would make them continue conservative care, what would make them modify it and what would make them urgently escalate.