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Clinical Efficacy of an Innovative Multidimensional Traction Therapy in Moderate Adolescent Idiopathic Scoliosis
Published on: February 10, 2026
Right thoracic curvature in the normal spine
Toshio Doi1, Katsumi Harimaya, Hiromichi Mitsuyasu
1Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan. toshidoi@ortho.med.kyushu-u.ac.jp
Journal of Orthopaedic Surgery and Research
|January 15, 2011
Summary
Normal spines show a shift towards right thoracic curvature after adolescence. This finding in healthy individuals may help understand the causes of adolescent idiopathic scoliosis (AIS).
Area of Science:
- Orthopedics
- Radiology
- Spinal Health
Background:
- Trunk asymmetry and vertebral rotation in normal spines can mimic adolescent idiopathic scoliosis (AIS).
- Right thoracic curvature is a noted characteristic in some healthy spines.
- Understanding normal right thoracic curvature may offer insights into AIS etiology.
Purpose of the Study:
- To investigate the prevalence and characteristics of right thoracic curvature in normal spines.
- To compare thoracic curvature patterns across different age groups (children, adolescents, adults).
- To determine if normal right thoracic curvature resembles that seen in AIS.
Main Methods:
- Evaluated 1,200 posteroanterior chest radiographs from children, adolescents, and adults (ages 4-29).
- Measured Cobb angles (T5-T12) in normal spines using the same range as scoliosis curves.
- Classified curves as neutral (-1° to 1°), right (> +1°), or left (< -1°), with right curvature as positive.
Main Results:
- Thoracic curvature shifts to the right in adolescents (p < 0.01) and adults (p < 0.001) compared to children.
- No significant difference in curvature pattern was found between adolescent and adult groups.
- Specific Cobb angle values for left, neutral, and right curves were documented for each age group.
Conclusions:
- Standing chest radiographs reveal a tendency for right thoracic curvature in normal spines post-adolescence.
- This age-related shift in normal spinal curvature warrants further consideration in scoliosis research.
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