Triaging and Red Flags

Triaging is sorting sufferers into groups in order to deliver appropriate management to each group.  In particular, with reference to LBP, the main purpose of triage is to determine which sufferers may have LBP of pathological origin e.g. infection, neoplasm (cancer), significant trauma, inflammatory.

In medical terms, the three groups of lower back pain and sciatica sufferers are:

  • Pathology
  • Nerve compression
  • Non-specific LBP


Fortunately – having screened out the pathological causes – the management of the remaining 99% (approx) is much the same (as my review of clinical guidelines).

The Red Flag questions below also serve to commence the triage process.  Any “yes” to the below is flagged by the AXB system and we recommend the client has an online clinical consultation for further assessment.

NOTE that includes screening for red flags “Should you see your doctor”.  You may copy the questions in this course, or simply encourage clients to use the chatbot – there is no charge 😉

Compared with during your waking day, is your pain worse when trying to sleep?

This question is predominantly about cancer pain, which is often worse at night.  Unfortunately, a lot of “mechanical” LBP and sciatica is worse after a brief period of lying down too.  When the person lies still, there can be a build up of inflammation in the area, making it more painful.  Intervertebral discs also absorb fluid when “off-weight-bearing” (lying down), so if there’s a bulge in the disc , the bulge gets bigger when lying down; disc-related spinal nerve pain is often worse at night and first thing in the morning.

Pain is often worse lying down at night because there are no sensory distractions.  There’s just you and your pain, which makes it seem worse than when you’re busy during the day.

So, although this question is included, a “yes” is often due to “mechanical” problems rather than “medical” ones.


Have you lost any great amount of weight without meaning to over the last year?

Unexpected weight loss is often a sign of underlying illness – such as cancer.


Have you been diagnosed with Cancer at any time?

Cancer can spread to bone, and other tissues potentially leading to pain.  A history of cancer, with recent onset pain – especially pain that is worse at night, and not obviously related to movement would warrant further investigation.


Have you had lower back surgery in the last 2 years?

A recent back operation that subsequently becomes painful may need to be reviewed by the surgeon.


Do you have any weakness (rather than pain) in any of the below?

  1. When standing, lifting either big toe up
  2. when standing, pushing up onto the toes of one foot (compared with the other, or compared with what you would expect is your normal)
  3. squatting


Muscle weakness is often a sign of “nerve compression”.  A doctor/osteopath/chiropractor/physio would conduct specific muscle testing and reflex testing to help in the diagnosis, and to decide whether further investigation is necessary.


Do you have any numbness (lack of sensation) or pins and needles in your pelvic floor area (up between your upper thighs, the area you would sit on if on a saddle)?

Numbness or pins and needles in this area could be a symptom of “cauda equina” – where a number of spinal nerves are involved at the same time.  This always requires further investigation.


Have you had any recent change in sexual function?  Loss of feeling, erection or ability to orgasm?

The nerves to the sexual organs originate in the lumbar spine.  These symptoms should always be investigated.


Do you have any difficulty urinating or defecating (using the toilet)?

Again, nerves to the bladder and bowel come from the lumbar and sacral areas, and could cause problems here.  This is less about pain when attempting these activities, and more about difficulty starting or stopping or having poor stream (in the case of urination).


Have you suffered any significant trauma recently, which in any way could impact on your lower back?

A big impact (like in a car accident), followed by pain could be a sign of serious injury and may need further investigation.  Best for a clinician to make this judgment.


Have you been on a prolonged course of oral corticosteroids (steroids by mouth) in the past or now?

Long-term steroid use can lead to osteoporosis, which in turn can cause micro-fractures in the bones leading to pain.


Have you had a persistent high temperature or chills recently?

This could be a sign of underlying illness such as an infection or some forms of cancer.



Some sufferers may initially answer “no” to all of these questions, but subsequently become a “yes”.  You may start out with mechanical back pain, but 3 months later the pain could be due to a different cause.  It’s worth encouraging clients to re-do this questionnaire monthly if the pain persists.


A note on diagnosis

Note that the Clinical Guidelines do not encourage the offering of a specific “tissue-based” diagnosis to sufferers.  In fact, as discussed by Nicholas & George (2011), “recent studies have highlighted the variability of pain intensity reports and the difficulty of precisely identifying specific lumbar anatomy to account for patients’ pain complaints. Collectively, these studies have indicated that an evidence-based pain management approach should not emphasize the identification of anatomical structures creating the pain.” (apart from in the identification of possible pathology).


The below table is included for information.  It can be used in determining which sufferers with lower extremity pain are likely to have referred pain, and which are likely to have pain due to spinal nerve irritation (radiculopathy).  “Non-Nerve Compression Sciatica” versus “Nerve Compression Sciatica”.


Table 5. Differentiating lower extremity referred pain from radicular pain

 Referred Pain NNCS
Radicular Pain NCS
QualityDeep achingSharp, shooting
 Poorly localisedWell localised
 Back worse than legLeg worse than back
 No pins and needlesUsually pins and needles
 Covers wide areaWell defined area
 No radicular or shooting painFollows radicular path
ModificationWorse with extensionWorse with flexion
 Better with flexionBetter with extension
 No radicular patternRadicular pattern
RadiationBelow knee unusualBelow knee common
 No radicular patternRadicular and shooting pain
Sensory changeUncommonProbably
Motor changeOnly subjectiveObjective weakness
Reflex changesNoneCommon
SLRTLBP only – no nerve root tension signsLeg pain, nerve root tension signs



Nicholas, M.K., George, S.Z., 2011. Psychologically Informed Interventions for Low Back Pain: An Update for Physical Therapists. Physical Therapy 91, 765–776.

No HTML was returned.