How Back Pain Is Assessed: Clinical Examination, X-ray, MRI and Other Tests

A patient guide from The Pain Relief Clinic, Singapore. Last updated 11 September 2026.

Back pain is not diagnosed from a scan alone. A clinician first considers the history, symptom pattern, warning signs, physical and neurological examination, and the patient’s functional needs. An X-ray, MRI or another test may then be considered if it is likely to answer a specific question or change the next step.

This guide explains what may happen during a back-pain assessment and what common findings can—and cannot—show. It is general education and cannot diagnose an individual.

The short answer: Many people with uncomplicated lower-back pain do not require immediate imaging. MRI becomes more relevant when there are serious or progressive neurological findings, concern about infection, tumour or cauda equina compression, persistent sciatica where an invasive procedure is being considered, new symptoms after spinal surgery, or diagnostic uncertainty where the result may change management. The decision should be based on the complete clinical picture rather than pain severity alone.

Seek urgent medical attention for possible warning signs

Urgent assessment may be needed if back pain is accompanied by:

• New loss of bladder or bowel control
• New numbness around the genitals, buttocks or inner thighs
• Severe or rapidly worsening weakness in one or both legs
• Back pain after significant trauma, especially with osteoporosis or frailty
• Fever, chills or significant illness with new back pain
• A history of cancer with new, persistent or unexplained back pain
• Unexplained weight loss or progressively worsening pain
• Severe pain in someone who is immunocompromised or at increased risk of infection

This list is not exhaustive. Symptoms that are severe, changing quickly or medically alarming should be assessed promptly rather than monitored using an online guide.

Why does assessment come before choosing a treatment?

The same words—“lower-back pain”—can describe very different situations. One patient may have a recent muscular or mechanical episode without nerve symptoms. Another may have pain travelling below the knee with weakness. A third may have back pain referred from the hip or an internal organ.

Assessment has four main purposes:

1. Identify symptoms that require urgent investigation or referral.
2. Distinguish uncomplicated back pain from possible nerve, fracture, inflammatory or systemic conditions.
3. Understand how pain affects work, sleep, mobility and daily function.
4. Decide whether a test would add useful information or change management.

The World Health Organization recommends thorough, person-centred assessment for chronic primary lower-back pain, including consideration of physical, psychological and social factors and timely referral where more detailed or urgent review is indicated.^[1]

Step 1: The clinical history

A useful assessment starts with listening. The clinician may ask about the following areas.

How and when did the pain start?

• Sudden or gradual onset
• Injury, fall, lifting episode or unfamiliar activity
• Recent illness, procedure or infection
• First episode or recurrent problem
• Symptoms lasting days, weeks or more than three months

Duration affects the questions being considered, but it does not establish a diagnosis by itself.

Where is the pain and where does it travel?

• Central or one-sided back pain
• Buttock, groin or hip pain
• Pain travelling into the thigh, calf, foot or toes
• Numbness, tingling, burning or electric sensations
• Symptoms in one leg or both

Pain travelling into a leg may raise the possibility of nerve-root involvement, but not every leg symptom is sciatica. Hip conditions, peripheral nerves, blood vessels and other structures can produce overlapping symptoms.

What aggravates or relieves it?

The clinician may ask about sitting, standing, walking, bending, coughing, lifting, sleep and repeated movement. These patterns can help generate or refine possible explanations, but they rarely identify one tissue with certainty.

Are there neurological or systemic symptoms?

Questions about weakness, altered sensation, bladder or bowel function, fever, weight loss, cancer history and recent infection help identify situations that may require urgent investigation.

What has already been tried?

Previous medication, physiotherapy, injections, manual treatment, imaging and surgery matter. “Physiotherapy did not work,” for example, may mean that the diagnosis, exercise selection, dosage, progression or ability to participate needs reassessment—not that every form of rehabilitation has failed.

What does the patient need to be able to do?

Returning to work, sleeping, walking, travelling, caring for someone or resuming sport may be more meaningful than a pain score alone. These goals help determine what improvement should look like and how urgently function needs to be addressed.

Step 2: The physical and neurological examination

The examination is selected according to the history. Not every patient requires every test.

Observation and function

The clinician may observe:

• Walking pattern and balance
• Ability to sit, stand and change position
• Spinal movement
• Functional tasks related to work or daily life
• Whether movement reproduces, centralises, spreads or relieves symptoms

Pain during movement is useful information, but it does not necessarily identify the exact structure causing the pain.

Strength, sensation and reflexes

A neurological examination may compare both legs for:

• Muscle strength
• Light-touch sensation
• Knee and ankle reflexes
• Heel walking, toe walking or other functional strength tasks
• Foot drop or another observable motor deficit

A pattern involving strength, sensation and reflexes can support possible nerve-root dysfunction. One minor difference, particularly without corresponding symptoms, may be less informative than several consistent findings.

Straight-leg-raise test

During the straight-leg-raise test, the patient lies down while the clinician gently raises the straightened leg. Reproduction of familiar pain radiating down the leg may support possible irritation of a lumbosacral nerve root. Back discomfort or hamstring tightness alone is not necessarily a positive result.

The test generally has relatively high sensitivity but low specificity for lumbar disc protrusion with nerve-root involvement. This means it can contribute useful information, but a positive result does not prove that a herniated disc is causing the symptoms. It must be interpreted alongside the pain distribution, strength, sensation, reflexes and, where appropriate, imaging.^[2][3]

Crossed straight-leg raise

During a crossed straight-leg raise, lifting the less symptomatic leg reproduces familiar symptoms in the opposite leg. This finding is less common and may be more specific for significant nerve-root irritation, but it still cannot establish a diagnosis alone.

Slump and femoral nerve-stretch tests

Other nerve-provocation tests may be selected according to the symptom distribution. The slump test can add information about neural sensitivity. A femoral nerve-stretch test may be considered when symptoms suggest an upper lumbar nerve-root pattern or pain at the front of the thigh.

These tests should be performed and interpreted by someone trained to distinguish neural symptoms from ordinary muscular stretch or joint discomfort. Patients should not use them to diagnose themselves.

Examination of the hip and other regions

The hip, sacroiliac region, abdominal area, peripheral nerves and circulation may be considered when the symptom pattern is not clearly spinal. This is especially important when groin pain, restricted hip movement, vascular symptoms or systemic features are present.

Palpation

Tenderness and muscular tension can identify sensitive areas, but palpation usually cannot confirm which deep spinal structure is causing pain. Tenderness should be interpreted as one part of the examination rather than a complete diagnosis.

What might common findings mean?

Possible finding	What it may contribute	What it does not prove by itself
Familiar leg pain during straight-leg raise	Possible nerve-root irritation	A definite disc herniation
Reduced ankle reflex with corresponding symptoms	May support a lower lumbar or sacral nerve pattern	The exact source or severity of compression
Measurable foot or leg weakness	Possible motor-nerve involvement requiring closer assessment	That surgery is automatically required
Pain altered by position or repeated movement	May help classify the mechanical or functional pattern	Which single tissue is responsible
Limited hip movement	The hip may contribute to the symptoms	That the lumbar spine is normal
Local muscular tenderness	Identifies a sensitive area	That the muscle is the primary cause
Normal basic neurological findings	Makes major neurological impairment less likely at that examination	That no nerve irritation or other problem exists
Abnormal MRI finding	Shows structural change	That the finding is necessarily causing the pain

The most useful conclusion usually comes from several findings that form a consistent pattern.

Step 3: Deciding whether imaging is likely to help

Major clinical guidelines advise against routinely imaging uncomplicated lower-back pain when serious disease is not suspected and the result is unlikely to change management.^[4][5]

This is not because pain is unimportant. It is because imaging can reveal common structural changes that are unrelated to the current symptoms, leading to anxiety, unnecessary procedures or treatment directed at the wrong finding.

Situations in which immediate imaging may not be necessary

Immediate imaging is often not the first step when:

• The pain is recent and uncomplicated
• There was no significant trauma
• There are no serious or progressive neurological findings
• There are no features suggesting infection, tumour or fracture
• The result would not change initial care

The patient should still be given safety-net advice explaining which new or worsening symptoms require reassessment.

When may an X-ray be considered?

An X-ray may be useful when the clinical question primarily concerns bone or alignment, including:

• Suspected fracture or vertebral collapse
• Significant trauma
• Increased fracture risk from osteoporosis, age, frailty or prolonged steroid exposure
• Selected alignment or structural questions
• Certain postoperative assessments

X-rays show bones better than discs, nerves and most soft tissues. They use ionising radiation and can show degenerative changes that do not necessarily explain pain.

An X-ray is therefore not simply a “basic MRI.” It answers different questions.

When may an MRI be considered?

MRI provides detailed images of discs, spinal nerves, the spinal canal, bone marrow and many soft tissues without ionising radiation. It may be considered when there is:

• Severe or progressive neurological impairment
• Concern about cauda equina compression
• Suspicion of spinal infection or tumour
• Persistent or progressive sciatica when an injection or surgical opinion is being considered
• New or changing symptoms after spinal surgery
• Continuing symptoms with diagnostic uncertainty when the result may materially change care
• A suspected specific condition for which MRI is the appropriate investigation

MRI is not perfect. Disc degeneration, bulges and other changes occur in many people without symptoms and become more common with age.^[6] A scan is most informative when a finding corresponds with the patient’s symptoms and examination.

Does severe pain automatically mean an MRI is needed?

No. Pain intensity alone does not determine the need for MRI. Severe pain can occur without dangerous structural disease, while some important neurological conditions may present with symptoms other than extreme pain. Urgency depends on the full history and examination.

Does pain lasting six weeks automatically mean an MRI is needed?

No fixed duration works for everyone. Persistent symptoms may make imaging more relevant, particularly if the result could change treatment or guide a procedure. Duration should be considered together with progression, neurological findings, prior care, diagnostic uncertainty and the planned next step.

Can MRI identify the exact cause of every case of back pain?

No. MRI shows anatomy, not pain itself. It may not identify every functional, muscular, inflammatory or pain-processing contributor. A normal or non-explanatory MRI does not mean the patient’s pain is imaginary.

When may CT be considered?

CT provides detailed images of bone. It may be used for:

• Selected fractures and trauma
• Complex bony anatomy
• Certain postoperative questions
• Situations in which MRI is unsuitable or unavailable

CT uses ionising radiation and is generally less informative than MRI for many disc, nerve and soft-tissue questions. The choice depends on the suspected condition, not which machine is considered more advanced.

Do ultrasound scans have a role in back pain?

Ultrasound has limited ability to examine structures deep inside the adult lumbar spine. It may be relevant when the clinician suspects a superficial soft-tissue problem, a hip-related problem, an abdominal or urinary cause, or another condition that ultrasound can assess appropriately.

Ultrasound should not be promoted as a direct alternative to lumbar MRI for examining spinal discs and nerve roots.

When may blood tests be considered?

Blood tests are not routinely required for uncomplicated mechanical back pain. They may be considered when the history or examination raises concern about:

• Infection
• Inflammatory disease
• Malignancy
• Metabolic bone disease
• Another systemic condition

The specific tests depend on the suspected condition. A mildly abnormal result should not be interpreted without its clinical context.

When may nerve-conduction studies or EMG be useful?

Electromyography and nerve-conduction studies assess aspects of nerve and muscle function. They may be considered when:

• Weakness, numbness or tingling persists
• The affected nerve or level is unclear
• A peripheral nerve condition must be distinguished from a spinal nerve-root problem
• Symptoms, examination and imaging do not correspond clearly

These tests do not replace MRI because they answer different questions: MRI shows anatomy, while electrodiagnostic testing assesses aspects of function.

When may a bone-density scan be relevant?

A DEXA scan measures bone density and helps assess osteoporosis and fragility-fracture risk. It does not ordinarily locate the direct cause of back pain.

It may be relevant for older adults, people with a fragility fracture, prolonged steroid exposure or other osteoporosis risk factors. If an acute vertebral fracture is suspected, different imaging may also be required.

Which test might be considered in different situations?

Clinical situation	Possible investigation approach	Important qualification
Recent uncomplicated lower-back pain	Often no immediate imaging	Reassess if warning signs or neurological symptoms develop
Significant trauma or suspected fracture	X-ray and/or CT; MRI in selected cases	Choice depends on stability, neurological findings and fracture type
Possible cauda equina compression	Urgent MRI and urgent specialist pathway	This should not wait for routine outpatient monitoring
Progressive weakness or neurological loss	MRI and appropriate referral may be required	Urgency depends on severity and progression
Suspected infection or tumour	MRI and selected blood tests	Requires timely medical assessment
Persistent sciatica despite appropriate care	MRI may be considered if it could guide an injection or surgery	Imaging should correspond with the clinical pattern
Suspected spinal stenosis with limiting leg symptoms	MRI is commonly considered	Symptoms and function remain important to interpretation
New symptoms after spinal surgery	MRI or CT depending on the question	Contrast may be considered in selected postoperative situations
Possible inflammatory back disease	Blood tests and specialist-directed imaging may be considered	No single blood test confirms every inflammatory spinal condition
Osteoporosis or fragility risk	DEXA for bone density; X-ray, MRI or CT if fracture is suspected	DEXA does not diagnose the pain source
Persistent unexplained nerve symptoms	MRI and/or EMG or nerve studies	These tests provide different types of information

This table is educational rather than a personal investigation recommendation.

What if the MRI report says “degeneration,” “disc bulge” or “slipped disc”?

Structural findings should be translated into clinical meaning rather than treated as a diagnosis by themselves.

Questions to ask include:

1. Does the level and side of the finding match the symptoms?
2. Does the examination support involvement of the corresponding nerve or structure?
3. Is the finding common for the patient’s age?
4. Would treatment change because of this result?
5. Are there other possible contributors to the pain or disability?

A systematic review found that degenerative imaging features are common in people without back pain and increase with age.^[6] This does not make MRI unhelpful; it means interpretation matters.

What if the MRI is described as normal but pain continues?

A normal or non-explanatory MRI does not invalidate symptoms. Possible next questions include:

• Was the correct anatomical region examined?
• Has the symptom pattern changed since imaging?
• Does the clinical examination suggest a hip, peripheral nerve or non-spinal source?
• Are movement, muscular, sleep, work or pain-processing factors contributing?
• Is another test actually likely to change management?
• Does the treatment plan need to focus more on function than structural correction?

Repeating MRI without a new clinical question may not provide a better answer.

What if physiotherapy has not helped?

Before assuming that more invasive treatment or more imaging is required, reassessment can examine:

• Whether the original diagnosis remains plausible
• Whether there are new leg symptoms, weakness or numbness
• What exercises or treatments were actually performed
• Whether dosage and progression were suitable
• Whether pain prevented meaningful participation
• Whether work, sleep, stress or fear of movement affected recovery
• Whether imaging would now change the plan

The objective is not to defend or dismiss the previous treatment. It is to determine why the expected improvement did not occur and what information is missing.

What if the patient must return to work quickly?

A time-sensitive assessment can focus on safe function:

• Which job tasks are currently limited?
• Are any warning signs present?
• Is temporary modified duty possible?
• What symptom-management options are reasonable?
• Which movements and activities can be maintained?
• What findings would require escalation or imaging?

The immediate goal may be safe participation rather than total pain elimination. Neither examination nor imaging can guarantee recovery by a fixed date.

How The Pain Relief Clinic may help

The Pain Relief Clinic in Singapore provides assessment by a licensed medical doctor together with physiotherapy and selected non-invasive care. The consultation can review the patient’s symptoms, examination findings, previous treatment and functional priorities.

Where an investigation is clinically indicated, the clinic can help arrange an appropriate X-ray, ultrasound or MRI and review how the result relates to the clinical picture. The clinic may also recommend referral when another service or specialist assessment is more appropriate.

An appointment does not guarantee that imaging or any particular treatment will be recommended. The purpose is to identify the next reasonable step based on the individual situation.

To arrange an assessment, call +65 9068 9605.

Frequently asked questions

Is MRI safer than X-ray because it has no radiation?

MRI does not use ionising radiation, while X-ray and CT do. However, the safest and most useful test is the one that is clinically appropriate. MRI also has contraindications and practical limitations that must be checked.

Can an X-ray show a slipped disc or pinched nerve?

An ordinary X-ray does not directly show spinal discs and nerve roots well. It may show indirect bony or alignment findings, but MRI is generally more informative when the clinical question concerns discs, nerves or the spinal canal.

Should everyone with sciatica have an MRI?

No. Some cases can initially be managed without imaging when serious or progressive neurological problems are not suspected. MRI becomes more relevant when symptoms persist or progress, important neurological findings are present, or an invasive procedure is being considered.

Can a straight-leg-raise test diagnose a slipped disc?

No. Reproduction of familiar radiating leg pain may support nerve-root irritation, but the test is not sufficiently specific to prove a disc herniation by itself.^[2][3]

Can back pain be real when both the examination and MRI are normal?

Yes. Pain is not measured directly by MRI, and routine examination and imaging do not capture every possible contributor. Persistent symptoms deserve a thoughtful functional and clinical reassessment rather than dismissal.

Is the most detailed scan always the best choice?

No. Different tests answer different questions. More detail can also reveal incidental abnormalities that do not explain the symptoms. The best investigation is the one most likely to clarify an important diagnosis or change management.

Key points

• The history and examination come before choosing a test.
• Urgent warning signs require prompt medical assessment.
• No single examination manoeuvre can diagnose every cause of back pain.
• Straight-leg raise can support possible nerve-root irritation but cannot prove a disc herniation alone.
• Routine imaging is not required for every episode of back pain.
• X-ray, MRI and CT answer different clinical questions.
• MRI abnormalities must be matched to symptoms and examination findings.
• A normal MRI does not mean that pain is imaginary.
• Imaging is most valuable when the result may change what happens next.

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References

1. World Health Organization. WHO guideline for non-surgical management of chronic primary low back pain in adults in primary and community care settings. 2023.
2. Camino Willhuber GO, Piuzzi NS. Straight Leg Raise Test. NCBI Bookshelf.
3. Tawa N, Rhoda A, Diener I. Accuracy of clinical neurological examination in diagnosing lumbo-sacral radiculopathy: a systematic literature review. BMC Musculoskeletal Disorders. 2017;18:93.
4. National Institute for Health and Care Excellence. Low back pain and sciatica in over 16s: assessment and management (NG59).
5. American College of Radiology. ACR Appropriateness Criteria: Low Back Pain.
6. Brinjikji W, et al. Systematic Literature Review of Imaging Features of Spinal Degeneration in Asymptomatic Populations. AJNR. 2015;36(4):811–816.