Scoliosis: How to Use a Scoliometer

Definition & Etiology

Scoliosis is defined as a lateral curvature of the spine that is 10º or greater on a coronal radiographic image while the patient is in a standing position (measured using the Cobb method)

Cobb method: 

  • A line is drawn along the superior endplate of the top vertebra in the curve, which will be the endplate most tilted off of horizontal. A second line is drawn from the inferior endplate of the bottom vertebra of the curve, determined in the same manner (see figure below). This angle can be measured with a protractor on hard copy radiographs or digitally on a computer screen.

The most common etiology of scoliosis is idiopathic, affecting 85% of patients with scoliosis. Other etiologies include congenital, neuromusclar (e.g., cerebral palsy, muscular dystrophy), and syndromic (e.g., connective tissue disorders). 

Patients with idiopathic scoliosis are most often asymptomatic, recognized on routine screening. For patients with symptoms, the most common presentation is mild back pain. 

To Screen or Not To Screen

Position Statement from The Scoliosis Research Society:

  • “The Scoliosis Research Society (SRS), American Academy of Orthopedic Surgeons (AAOS), Pediatric Orthopedic Society of North America (POSNA) and American Academy of Pediatrics (AAP) believe that screening examinations for spine deformity should be part of the medical home preventative services visit for females at age 10 and 12 years, and males once at age 13 or 14 years.”

Position Statement from USPSTF:

  • “The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of screening for adolescent idiopathic scoliosis in children and adolescents aged 10 to 18 years.”

Advocates of screening point out that the use of bracing in selected skeletally immature children may reduce the need for surgery. Opponents note that few children with scoliosis need active treatment and that there is a high false-positive rate of referrals, limiting the value of screening. 

Exam Approach to Screening

When the spine curves, it also rotates in a characteristic manner: the convex side rotates up (dorsally) and the concave side rotates down (ventrally). This rotational asymmetry is the classic physical finding in scoliosis. It is the basis for the Adams forward bend test used to screen for scoliosis.

Adam’s forward bend test: 

  • Inspect the patient’s spine while they bend forward, trying to touch their toes. Look for rotational asymmetry, which is often most pronounced in the thoracic spine
  • Rotational asymmetry can be measured with a scoliometer (aka inclinometer), which should be placed at the apex of the deformity. The reading on the scoliometer tells us the angle of trunk rotation. An abnormal ATR is ~7º, which roughly corresponds to a Cobb angle of 20º

Radiography remains the gold standard for confirming a diagnosis of scoliosis. Standing thoracolumbar XR is preferred because supine images can underestimate the true magnitude of a patient’s scoliosis. 

Patients with a Cobb angle >20º should be referred to orthopedics. 


Treatment approach depends on severity: 

  • Cobb angle <10º: Patients can be reassured that they do not have a clinically significant curve, and further imaging is not necessary
  • Cobb angle <20º: Patients should be followed closely and rechecked in 6 months
  • Cobb angle >20º: Skeletally immature children may be referred to orthopedics. Skeletally mature children with curves <30º can be reassured that the risk of progression is very low, but those with curves >30º should be referred to orthopedics.


  • Goal: Prevent progression to surgery
  • Progression dictated by skeletal age
  • Ideal patient: Cobb angle 30-50º with skeletal immaturity
  • Bracing to be worn ≥13 hours per day (ideally >18 hours)
  • XR evaluation every 4-6 months

Evidence limited for PT, although may help with back pain. 


  • Typically reserved for patients with Cobb angle >50º

Take-Home Points!

  • Scoliosis is defined as Cobb angle >10º, but no indication for treatment until >20º
  • Idiopathic scoliosis is commonly recognized on routine exam/screening
  • Progression is entirely determined by skeletal maturity
  • Back bracing must be worn >12 hours per day to prevent progression
  • Surgery indicated for Cobb angle >50º

Blog post based on Med-Peds Forum talk by Sam Masur, PGY4

Scroll to Top