A scoliometer reading below 5° is generally considered low. 7° is the threshold most screening programmes use to refer someone to a healthcare professional. These are screening guidelines — not a diagnosis, and not a measure of the spinal curve itself.
A scoliometer records the Angle of Trunk Rotation (ATR): how much one side of the trunk rises above the other when a person bends forward. Because it measures rotation at the surface of the back rather than the spine itself, a reading is best understood as a signal about whether further assessment is worthwhile — not as a number that describes the spine.
Scoliometer reading ranges at a glance
| Reading | Commonly interpreted as | Usual next step |
|---|---|---|
| 0°–4° | Low; small asymmetries are common in the general population | Continue routine monitoring, particularly through growth spurts |
| 5°–6° | Worth attention; the usual referral point for overweight children, in whom curves are harder to see | Re-measure carefully; consider professional review |
| 7° or more | The commonly accepted referral threshold in screening programmes | Seek professional assessment |
| Rising by 2° or more | Progression signal, regardless of the absolute value | Seek professional review |
Why 7° is the usual referral point
Screening thresholds are a trade-off. Set the referral line too low and large numbers of healthy children are sent for imaging they do not need; set it too high and curves that would benefit from early attention are missed. Around 7° is where most screening programmes have settled as a workable balance, with 5° used for children who are overweight because a curve is more easily hidden. Individual programmes and clinicians may use slightly different cut-offs, and results vary based on age, skeletal maturity, curve type and the consistency of the measurement.
Is there a UK threshold?
No. No UK body — not the National Screening Committee, not the NHS, not NICE, not the British Scoliosis Society — publishes an angle of trunk rotation or scoliometer figure at which a child should be referred. This is a verified absence rather than a gap in our research: the Government’s 2018 response to a petition calling for school screening gave the lack of an agreed cut-off as one of its reasons for declining. You may see 5° to 7° quoted in UK material, including in the Screening Committee’s own 2021 evidence map, but there it is explicitly described as an American recommendation, not a British one.
That leaves the international range as the honest frame. Much of the published literature treats 5° to 7° as the band in which a rotation becomes worth investigating, and these guides use 7° as the reading that clearly warrants a professional opinion. Because no UK threshold exists for a GP to work from, what you bring to the appointment matters more here than in countries with a school programme: a series of dated readings showing a curve that is increasing is a far stronger reason for referral than a single measurement on the day.
What a reading does not tell you
- It is not the Cobb angle. The Cobb angle is measured on an X-ray and is the diagnostic measurement. ATR and Cobb angle are related but not interchangeable — see what a scoliometer measures.
- It does not give a severity grade. A 9° reading is not “moderate scoliosis”; it is a reason to be assessed.
- It does not rule scoliosis out. A low reading with visible asymmetry, back pain or a family history still deserves professional review.
- It says nothing about progression risk on its own. Age, skeletal maturity and growth stage carry more weight than a single number.
The trend matters more than the number
One reading is a snapshot. A series taken the same way, by the same person, at consistent intervals is far more informative. An ATR that climbs steadily over a few months is meaningful even while each individual reading still looks modest — and a reading that jumps once, then returns to baseline, is more likely to reflect technique than change. This is why recording the date, the region measured and who measured is worth the extra few seconds. For technique, see how to use a scoliometer.
Readings in children versus adults
In children and adolescents the concern is progression during growth, so readings are usually repeated more often — roughly every two to four weeks through a growth spurt — and a rising trend is acted on promptly. In adults, skeletal growth is complete and change tends to be slower, driven by degenerative factors rather than growth; monthly monitoring is usually sufficient, with attention to symptoms alongside the number. In both cases the referral thresholds above are a starting point for a conversation with a professional, not a substitute for one.
When to seek professional review
Seek an assessment if a reading reaches the referral threshold, if readings are rising over time, or if you notice uneven shoulders, a prominent shoulder blade, an uneven waistline or a visible rib hump on forward bending. Outcomes and appropriate management vary between individuals; a professional examination is the way to establish what a reading means for a specific person.
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Frequently asked questions
- What is a normal scoliometer reading?
- Below 5° is generally considered low. Small trunk asymmetries are common, so a reading of 0° is not required for a back to be considered unremarkable on screening.
- Is a 5 degree scoliometer reading a problem?
- Not on its own. It is a reason to re-measure carefully and to consider professional review — and it is the usual referral point for children who are overweight.
- What does a 7 degree scoliometer reading mean?
- Around 7° is the threshold most screening programmes use to refer someone for professional assessment. It indicates that further examination is warranted, not that scoliosis is present.
- Does a scoliometer reading equal the Cobb angle?
- No. ATR is measured on the surface of the back; the Cobb angle is measured on an X-ray. Higher ATR tends to accompany a larger curve, but the relationship is approximate and varies between individuals.
- What if the reading goes up between measurements?
- An increase of 2° or more warrants professional review even if the absolute reading still looks modest. Confirm the technique was identical first, then seek an assessment.
Related guides
- ATR versus Cobb angle — why a scoliometer reading is not a curve measurement.
- How to use a scoliometer — the technique that makes readings comparable over time.
- Adam’s Forward Bend Test — the screening position and what an observer looks for.
- What is a scoliometer? — the instrument and the measurement explained.
Reference: van West HM, Herfkens J, Rutges JPHJ, et al. The smartphone as a tool to screen for scoliosis, applicable by everyone. European Spine Journal 2022;31:990–995. This research assessed smartphone-based ATR screening as a method and did not evaluate any specific application.