01/29/2026
🦴 Thoracic Scoliosis Biomechanics — Convex vs Concave
Thoracic scoliosis is a three-dimensional spinal deformity involving sideways curvature, vertebral rotation, and rib cage distortion. The spine doesn’t simply bend—it twists under gravity and muscle forces, creating uneven stress across the spine and rib cage.
🔄 Convex Side
On the convex side, ribs are pushed outward, placing muscles like the erector spinae and intercostals in a lengthened but weak position. Despite appearing “long,” these muscles often lack strength and stability. Posterior rib rotation contributes to the rib hump and reduces thoracic mobility and effective lung expansion.
đź”’ Concave Side
On the concave side, ribs move closer together and muscles become shortened, tight, and overactive. This increases compression on vertebrae and joints, leading to stiffness, discomfort, and restricted movement. Anterior rib rotation further limits breathing capacity.
⚙️ Disc & Vertebral Loading
Asymmetric muscle forces cause increased compression on the concave side and tensile stress on the convex side, which may contribute to curve progression, especially during growth.
🚶 Posture & Breathing Effects
To stay balanced, the body compensates through the shoulders, pelvis, and gait, increasing fatigue. Uneven rib movement leads to asymmetric breathing and reduced endurance.
đź©ş Key Clinical Insight
Effective correction focuses on decompressing the concave side, activating weak convex-side muscles, improving mobility, posture, and breathing—using curve-specific exercises, not generic strengthening.
