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.
| 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 about 5° | Progression signal, regardless of the absolute value | Seek professional review |
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.
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.
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.
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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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.