What Is Scoliosis? Signs, Types and Diagnosis

Scoliosis is a sideways curvature of the spine that is always accompanied by rotation of the vertebrae. Thinking of it only as a "sideways bend" is incomplete — because of that rotation, scoliosis is treated as a three-dimensional problem.

A sideways deviation of less than 10 degrees is not called scoliosis; it is considered asymmetric posture. For a diagnosis, the measured angle needs to exceed 10 degrees and be accompanied by rotation.

Structural versus non-structural

Separating the two matters because it determines the path forward.

• Structural scoliosis: a permanent change in the shape and rotation of the vertebrae. It does not disappear on forward bending.
• Non-structural (functional) curvature: caused by a leg length difference, muscle spasm or a pain-avoidance posture. It resolves once the underlying cause is addressed.

Types

Idiopathic scoliosis is by far the most common. "Idiopathic" means the cause is not fully known; genetic predisposition, growth velocity and differences in neuromuscular control are all discussed. It is most often noticed during the adolescent growth spurt.

Congenital scoliosis results from differences in spinal development before birth and follows a different monitoring protocol.

Neuromuscular scoliosis accompanies conditions affecting muscles and nerves, such as cerebral palsy. Trunk control and sitting balance are the priorities here.

Degenerative (adult) scoliosis develops later in life with wear of the discs and facet joints. The main complaint is usually back pain and reduced walking distance rather than appearance.

How it is noticed

Scoliosis usually announces itself through asymmetry rather than pain:

• One shoulder sitting higher than the other
• One shoulder blade standing out more
• Uneven gaps between the arms and the waist
• One hip appearing higher
• Clothing hanging unevenly

No single sign confirms a diagnosis, but any of them justifies a medical assessment.

The diagnostic pathway

Adams forward bend test

The person bends forward with straight knees while the back is observed from behind. In structural scoliosis the rotation produces a visible rib hump on one side. It is a quick, harmless screening test.

Scoliometer

Measures the trunk rotation angle during forward bending. Values around 5–7 degrees and above are generally used as the threshold for requesting an X-ray.

X-ray and the Cobb angle

The definitive diagnosis is made with a standing full-spine X-ray. The size of the curve is measured as the Cobb angle, and treatment decisions are based largely on this value together with age and remaining growth.

Growth potential

The Risser sign and, in girls, the age at first menstruation help estimate the risk of progression. The more growth remains, the closer the follow-up.

Where physiotherapy fits

Management is led by the treating physician. Physiotherapy is planned within that process, according to curve size, age and growth status. Scoliosis-specific exercise differs from general strength training: the aim is three-dimensional correction against the person's own curve pattern, combined with breathing control. You can read how that works in the Schroth method article.

When to seek assessment

If asymmetry is noticed in a growing child, there is no reason to wait. The value of early detection is not "reversing" the curve — it is being able to monitor closely during rapid growth and intervene in time if needed.