Every screening measurement eventually arrives at the same question: is this a number to act on, or a number to note and move past? This guide sets out the referral thresholds the evidence actually supports, the signs that warrant an appointment whatever the reading says, and what happens once you are in the room.
The referral threshold is a band, not a number
Parents often want a single cut-off. The evidence does not supply one. According to PubMed, the Scoliosis Research Society, SOSORT, IRSSD and the Paediatric Orthopaedic Society of North America jointly reviewed the screening literature and concluded that the scoliometer is the best available screening tool, and that there is moderate evidence supporting referral at values between 5° and 7° of trunk rotation (Labelle et al., Scoliosis, 2013; PMID 24171910; DOI 10.1186/1748-7161-8-17).
The same statement found moderate evidence that screening detects scoliosis at an earlier stage, when conservative treatment is more likely to help, and strong evidence supporting bracing for curves that qualify for it. That is the practical case for screening: not that every reading matters, but that the ones that do are worth finding early.
Where a clinician sits within the 5°–7° band depends on what they are optimising for. A lower threshold catches more curves and refers more children who turn out to be fine. A higher threshold refers fewer children and misses more curves. Neither is wrong; they are different trade-offs.
Why body build shifts the threshold
One finding is worth knowing if a child is heavier or lighter than average. Also according to PubMed, a review of 483 patients aged 10 to 18 found that patients with obesity presented with a mean major curve of 44° compared with 34° in those of normal weight, and were roughly five times more likely to present already at 20° or more (Margalit et al., Journal of Paediatric Orthopaedics, 2017; PMID 27861214; DOI 10.1097/BPO.0000000000000899). Soft tissue masks the surface rotation that screening depends on, so the curve grows further before anything shows.
The authors calculated referral thresholds adjusted for body mass to keep detection consistent across body types:
| Body mass category | Suggested ATR referral threshold |
|---|---|
| Underweight | 8° |
| Normal weight | 7° |
| Overweight | 6° |
| Obese | 5° |
These are research-derived thresholds intended for clinicians, not a rule you need to apply yourself. The useful takeaway for a parent is simpler: in a heavier child, a smaller reading deserves more attention, not less.
What a positive screen actually means
A reading above the threshold is a reason to be assessed. It is not evidence that scoliosis is present, and this is where most of the anxiety around screening comes from.
According to PubMed, an evaluation of a large school screening programme in Hong Kong — 442 children with a mean Cobb angle of 14.0° ± 6.6° — reported the programme as approximately 88% sensitive with a false-positive rate above 50% (Pang et al., Ultrasound in Medicine & Biology, 2021; PMID 34210559; DOI 10.1016/j.ultrasmedbio.2021.05.020).
Read that in both directions. Screening finds most of the curves that are there, which is the point of doing it. But more than half of the children it flags do not have a curve that needs treatment. If your child has been referred, the statistically most likely outcome is reassurance.
Signs that warrant assessment whatever the number says
A scoliometer measures one thing: rotation of the trunk at the level you place it. It can be normal in a curve that is real — single lumbar curves in particular often produce little surface rotation. Do not let a low reading talk you out of an assessment when something else looks wrong.
Seek an appointment if you notice any of the following:
- Uneven shoulders, or one shoulder blade more prominent than the other.
- A waist that is asymmetric, or a hip that sits higher on one side.
- A visible rib or lumbar prominence when bending forward.
- Clothing that consistently hangs unevenly, or a bra strap that slips on one side only.
- The head not appearing centred over the pelvis.
- Back pain that wakes the child at night, or pain that is worsening rather than fluctuating.
- Any neurological symptom — numbness, tingling, weakness, changes in balance or coordination, or changes in bladder or bowel function.
- A known curve in a child who is growing rapidly, regardless of the current reading.
Findings that make a clinician look beyond idiopathic scoliosis
Most adolescent scoliosis is idiopathic — it has no identifiable underlying cause. A minority is not, and certain features raise that possibility enough that a specialist may request an MRI. This is background context, not something to self-assess, but it explains why a clinician asks the questions they ask.
According to PubMed, a study of 714 adolescents with presumed idiopathic scoliosis found intramedullary abnormalities in 9.5%, with the strongest associations being male sex (odds ratio 2.99), a left thoracic curve (3.49), a sharp angular curve (4.82), an abnormal abdominal wall reflex (3.94) and ankle clonus (8.08) (Xu et al., BMC Musculoskeletal Disorders, 2020; PMID 32209088; DOI 10.1186/s12891-020-3182-z).
The signal is stronger in younger children. Again according to PubMed, among 504 infantile and juvenile cases labelled presumed idiopathic, 18.7% had neural axis abnormalities — most commonly Chiari malformation with or without syringomyelia — with male sex, a left thoracic curve and a right lumbar curve significantly associated (Zhang et al., BMC Musculoskeletal Disorders, 2016; PMID 27121616; DOI 10.1186/s12891-016-1026-7).
Back pain is more nuanced than it is often presented. In 152 adolescents with painful idiopathic scoliosis, MRI showed some underlying pathology in 35.5%, but only 3.9% had a neural axis abnormality, and imaging did not change orthopaedic management; lumbar pain location was the feature that correlated with finding something (Ramírez et al., Spine Deformity, 2020; PMID 32072489; DOI 10.1007/s43390-020-00065-w), also according to PubMed. Pain is worth reporting. It is not, by itself, a sign that something serious has been missed.
Who to see
The right first appointment depends on where you are, but the practical options are similar everywhere:
| Who | Best for |
|---|---|
| Family doctor or paediatrician | A first opinion, a physical examination, and a referral onward if needed. Usually the fastest route. |
| Physiotherapist experienced in scoliosis | Postural and functional assessment, exercise-based management, ongoing monitoring. |
| Chiropractor experienced in scoliosis | Structural assessment, conservative management, monitoring between specialist reviews. |
| Orthopaedic spine specialist | Radiographic Cobb angle measurement, bracing decisions, surgical opinions where relevant. |
The phrase that matters when booking is “experienced in scoliosis.” Scoliosis assessment is a specific skill, and a clinician who sees it regularly will interpret both the examination and the imaging differently from one who sees it rarely.
Getting assessed on the NHS
The route starts with a GP. NHS advice is to see a GP if you think you or your child has scoliosis, and if the GP suspects it they should refer you to a specialist through the NHS e-Referral Service. The British Scoliosis Society describes that onward referral as going to a spine surgeon, a paediatrician or an orthopaedic surgeon at a hospital, where the diagnosis is confirmed by X-ray. At a specialist scoliosis service the child is usually seen by a multidisciplinary team that includes a spine surgeon, specialist physiotherapists and specialist nurses. Some local NHS guidance treats a child under 11, or one with neurological symptoms or night pain, as an urgent referral.
Because there is no screening programme behind you, the GP appointment is the whole gateway, and it is worth preparing for. Bring your dated readings, photographs taken from behind in the same light and posture, and a note of when you first noticed a change. A curve that has visibly increased over two or three recorded measurements is concrete evidence in a system that has no threshold of its own to apply.
What actually happens at the appointment
Knowing the shape of the visit removes most of the apprehension. Expect some combination of:
- History. Age, growth pattern, when periods started if relevant, family history of scoliosis, pain, and any neurological symptoms.
- Postural examination. Shoulder and pelvic level, waist symmetry, head position over the pelvis, and how the trunk sits in standing.
- Adam’s Forward Bend Test with a scoliometer. The same test you have been doing at home, performed by someone doing it every week.
- A brief neurological screen. Reflexes, abdominal wall reflex, and coordination — quick, painless, and the reason the findings above are checked routinely.
- A decision about imaging. A standing full-spine X-ray if the examination warrants it. This is what produces a Cobb angle; nothing before this point can.
- A plan. Either a monitoring interval, a conservative treatment programme, a bracing discussion, or discharge.
What to bring
- Your record of readings, with dates, spinal level and who took each one.
- Photographs from the back and from the forward bend position, taken the same way each time.
- Height measurements over time, which tell the clinician where the child sits in their growth.
- Any previous imaging, including reports, not just the images.
- Family history of scoliosis, including relatives who were braced or operated on.
A dated series of measurements is worth considerably more than a single number on the day. Trend is the information a clinician cannot get from examining your child once.
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What “wait and see” really means
Many families leave an appointment with a curve that has been measured and a recommendation to come back in six months. It can feel like nothing has happened. It has.
Observation is an active decision that a curve is currently below the threshold at which intervention changes the outcome, taken with the knowledge that the child still has growth remaining and that the situation will be re-measured before that growth is spent. It is a plan with a review date, not an absence of one.
What makes it work is that the review actually happens. What makes it fail is a family that hears “nothing to worry about,” stops measuring, and returns two years later. If you are told to wait and see, ask three questions before you leave: what specifically are we watching, what change would bring us back sooner, and when is the next appointment. Continuing to take your own readings between visits is what turns the wait into monitoring.
Frequently asked questions
- What scoliometer reading means I should see a doctor?
- An international expert statement found moderate evidence supporting referral at trunk rotation values between 5° and 7°. Repeat the measurement carefully first; if it holds at 5° or more in a growing child, or 7° or more at any age, arrange an assessment.
- Does a raised reading mean my child has scoliosis?
- No. School screening programmes detect most curves but produce false positives in more than half of the children they flag. A raised reading is a reason to be assessed, not a diagnosis.
- Should I see a doctor if the reading is normal but the back looks uneven?
- Yes. A scoliometer measures rotation at the level you place it, and some curves — particularly single lumbar curves — produce little surface rotation. Visible asymmetry is worth assessing regardless of the number.
- Who should I see first for suspected scoliosis?
- A family doctor or paediatrician is usually the fastest route and can refer onward. A physiotherapist or chiropractor experienced in scoliosis can also assess and monitor. An orthopaedic spine specialist is the right destination if imaging, bracing or surgical questions arise.
- Will my child need an X-ray?
- Only if the examination warrants it. A standing full-spine X-ray is what produces a Cobb angle, which no surface measurement can provide. The decision belongs to the clinician after examining your child.
- Does back pain mean the scoliosis is serious?
- Not usually. In a study of adolescents with painful idiopathic scoliosis, imaging showed a neural axis abnormality in under 4%, and the findings did not change orthopaedic management. Report pain, particularly night pain or lumbar pain, but do not read it as evidence that something has been missed.
- What should I bring to the appointment?
- Your dated record of readings with the spinal level and who took each one, back and forward-bend photographs, height measurements over time, any previous imaging and reports, and family history of scoliosis. The trend is more informative than any single number.
- My clinician said to wait and see. Should I get a second opinion?
- Observation is a legitimate plan when a curve is below the threshold for intervention and growth remains. Before deciding, ask what is being watched, what change would bring you back sooner, and when the next appointment is. If those questions have no clear answers, a second opinion is reasonable.