Scoliosis screening: who is checked, the forward bend test, and what a positive screen leads to
The USPSTF found the evidence insufficient to weigh the benefits and harms of screening for scoliosis in children and adolescents aged 10 to 18 who have no symptoms (grade I). (USPSTF, 2018) Some US groups support screening, and the UK does not screen. (USPSTF, 2018)(UK NSC, 2021) This page explains how screening is done and what a positive screen leads to.
What adolescent idiopathic scoliosis is
Scoliosis is a sideways curve of the spine. Seen from behind, a typical spine looks straight; children and teens with scoliosis have an S-shaped or C-shaped curve. (NIAMS, 2023) Adolescent idiopathic scoliosis is a curve of unknown cause with a Cobb angle (a measure of the curvature of the spine) of at least 10 degrees, in children and adolescents aged 10 to 18. It is the most common form of scoliosis and usually worsens during adolescence before the skeleton is fully grown. (USPSTF, 2018)
- How common: an estimated 1% to 3% of children and adolescents aged 10 to 16 in the US have a Cobb angle of at least 10 degrees. (USPSTF, 2018)
- Girls and boys: a 10 degree curve is about as common in girls as in boys, but girls are 10 times more likely to progress to 30 degrees or more. (USPSTF, 2018)
- Family history: a child is more likely to have scoliosis if a parent, brother or sister has it. (NIAMS, 2023)
- Not from posture: the NHS says idiopathic scoliosis cannot be prevented and is not thought to be linked to things such as bad posture, exercise or diet. (NHS, scoliosis)
- By age: MedlinePlus groups idiopathic scoliosis as infantile (age 3 and younger), juvenile (4 through 10) and adolescent (11 through 18). (MedlinePlus, scoliosis) The NHS says it most often starts in children aged 10 to 15. (NHS, scoliosis)
Signs to report
Most children and teens with mild scoliosis have no symptoms or pain, and a child or family member may notice changes in posture. (NIAMS, 2023) Signs the sources list:
- Uneven tops of the shoulders, or one shoulder blade more prominent than the other. (NIAMS, 2023)
- One hip that looks higher than the other, or a tilted pelvis. (NIAMS, 2023)(MedlinePlus, scoliosis)
- One side of the rib cage higher than the other when bending forward. (NIAMS, 2023)
- A visibly curved spine, leaning to one side, or clothes not fitting well. (NHS, scoliosis)
MedlinePlus, when to contact a medical professional: "Contact your provider if you suspect your child may have scoliosis." (MedlinePlus, scoliosis) The NHS says to see a GP if you think you or your child has scoliosis; it is unlikely that anything is seriously wrong, but it is best to get it checked. (NHS, scoliosis)
The USPSTF recommendation covers children without symptoms. It does not apply to children seen for back pain, breathing difficulties, abnormal imaging findings or obvious curves of the spine. (USPSTF, 2018)
How screening is done
- Looking at the back: screening usually starts with a visual check of the spine for uneven shoulders, shoulder blades and hips. (USPSTF, 2018)
- Forward bend test: the clinician looks at the spine while the child stands upright, then while the child stands with feet together and bends forward at the waist, arms hanging and palms touching, and looks again. It is the test most often used in the US. (USPSTF, 2018) Bending forward makes the spine easier to see, though early changes can be hard to see. (MedlinePlus, scoliosis)
- Scoliometer: a device that measures the angle of trunk rotation and may be used during the forward bend test. An angle of 5 to 7 degrees is often the threshold for referral for an X-ray. (USPSTF, 2018)
- Other tests: a humpometer, the plumb line test, and Moiré topography, which creates a 3-dimensional image of the surface of the back. (USPSTF, 2018)
In the studies the USPSTF reviewed, accuracy was highest (93.8% sensitivity, 99.2% specificity) when 3 tests were used together, such as the forward bend test, scoliometer and Moiré topography. Sensitivity was 71.1% for the forward bend test with a scoliometer and 84.4% for the forward bend test alone. (USPSTF, 2018)
What a positive screen leads to
- A spine X-ray: if scoliosis is suspected, an X-ray is used to confirm the diagnosis and measure the curve (the Cobb angle). The Risser sign (the stage of ossification of the iliac apophysis) is used to monitor curve progression. (USPSTF, 2018) X-rays matter because the actual curve may be worse than what can be seen in an exam. (MedlinePlus, scoliosis)
- A history and exam: the doctor may ask about medical and family history, including other problems that might cause a curve. (NIAMS, diagnosis)
- Other imaging in some cases: MedlinePlus lists X-rays to see how flexible the curve is, MRI of the spine and CT scan of the spine. (MedlinePlus, scoliosis)
- What decides next steps: treatment depends on the degree of curvature and how much growth is left. (USPSTF, 2018) Children and teens with milder curves may just need regular check-ups. (NIAMS, 2023)
False positives: the USPSTF found false-positive rates from 0.8% to 21.5%. Potential harms of a false positive include unnecessary follow-up visits, a higher cancer risk from X-ray radiation, overtreatment, and psychosocial effects of a diagnosis of scoliosis that is not clinically significant. The USPSTF found no studies on the direct harms of screening. (USPSTF, 2018)
School screening
The USPSTF reported in 2018 that more than half of US states either mandate or recommend school-based scoliosis screening, usually with the forward bend test, with or without a scoliometer. (USPSTF, 2018) MedlinePlus says routine scoliosis screening is done in middle schools, (MedlinePlus, scoliosis) and NIAMS says some children are identified through school screening. (NIAMS, diagnosis) A school result is a screen, not a diagnosis: the diagnosis is made with an exam and X-rays. (NIAMS, 2023)
Where they differ:
| Group | What it says |
|---|---|
| USPSTF (US, 2018) | Children and adolescents aged 10 to 18 without symptoms: no recommendation, because the evidence is insufficient to weigh benefits and harms (grade I). (USPSTF, 2018) |
| AAOS, SRS, POSNA and AAP (US, 2016) | Screening girls at 10 and 12 years and boys once at 13 or 14 years as part of preventive care, if screening is done by well-trained screening staff (as summarised by the USPSTF). (USPSTF, 2018) (AAOS, SRS, POSNA, 2016) |
| SOSORT (international) | Screening through school-based programs, done by clinicians who specialise in spinal deformities (as summarised by the USPSTF). (USPSTF, 2018) |
| UK National Screening Committee (2021) | Screening is not recommended, because there is not enough evidence that finding the condition earlier through screening gives better health outcomes than waiting until symptoms develop. (UK NSC, 2021) |
- Why the USPSTF did not recommend either way: it found that screening tests can detect the condition accurately, but found no direct evidence on whether screening improves health outcomes, and inadequate evidence that reducing the curve in adolescence changes long-term health in adulthood. (USPSTF, 2018)
- Status: the USPSTF statement dates from January 2018; a literature scan in January 2025 found no new evidence to support an update. (USPSTF, 2018) The UK recommendation is based on its March 2021 review. (UK NSC, 2021)
More: USPSTF grades explained.
Your doctor decides what your result means for you.
This page does not give treatment advice, including on braces, exercises or surgery. If your child has a positive screen, see after an abnormal screening result for questions to ask.
Questions people ask
Should my child be screened for scoliosis?
Groups disagree. The USPSTF found the evidence insufficient to recommend for or against screening children and adolescents aged 10 to 18 who have no symptoms (grade I). US orthopaedic groups and the AAP support screening girls at 10 and 12 and boys once at 13 or 14. The UK National Screening Committee does not recommend screening. (USPSTF, 2018) (UK NSC, 2021)
What is the forward bend test?
The clinician looks at the spine while the child stands upright, then while the child stands with feet together and bends forward at the waist with arms hanging and palms touching. A scoliometer may be used during the test to measure the angle of trunk rotation. (USPSTF, 2018)
What happens after a positive scoliosis screen?
If scoliosis is suspected, an X-ray is used to confirm the diagnosis and measure the degree of curvature (the Cobb angle). X-rays matter because the actual curve may be worse than what can be seen in an exam. (USPSTF, 2018) (MedlinePlus, scoliosis)
What Cobb angle counts as scoliosis?
The USPSTF defines adolescent idiopathic scoliosis as a sideways curve of the spine of unknown cause with a Cobb angle of at least 10 degrees, in children and adolescents aged 10 to 18. (USPSTF, 2018)
Is school scoliosis screening required?
It depends on the state. The USPSTF reported in 2018 that more than half of US states either mandate or recommend school-based screening for scoliosis. (USPSTF, 2018)