📖 Static demo — read-only snapshot
You’re browsing a static build of the Body IQ knowledge graph, so everything loads with no backend. A few things that need the live server are turned off here:
- Global search (sidebar) is disabled — it queries the API.
- The JSON API and the API “Try it” playgroundaren’t included.
- The data is a snapshot — it refreshes only when the demo is rebuilt, not live from the database.
Everything else — the body map, progression ladders, coverage heatmap, exercise finder, and all anatomy/exercise/source pages — works fully. The full app (live search + API + database) runs from the source on GitHub.
Thoracic Extension
Thoracic Intervertebral Joints • Thoracic Spine • sagittal plane
Extension of the thoracic spine. Often limited by kyphosis and rib cage. Critical for overhead reaching.
Axis: medial-lateral
Normal Range of Motion
No single accepted goniometric norm for isolated thoracic extension; AAOS publishes only combined thoracolumbar values (extension 20-30 degrees). Magee cites isolated thoracic extension of roughly 25-45 degrees measured by inclinometer. Clinically assessed by dual inclinometry (T1/T12) or tape measure; value intentionally left null rather than asserting a precise norm.
Source: Magee, Orthopedic Physical Assessment; AAOS (thoracolumbar only)
Muscles (5)
| Muscle | Role | Notes |
|---|---|---|
| Erector Spinae Group | Primary | Thoracic portions: 64.9 ± 27.1% MVC in prone extension [De Ridder 2013] |
| Semispinalis Thoracis | Secondary | — |
| Multifidus | Secondary | Particularly at T5 [Lee 2005] |
| Rotatores (Thoracis) | Stabilizer | Segmental control; 89% Type I fibers |
| External Intercostals | Synergist | Rib elevation during inspiration; assists trunk extension |
Functional Tasks (3)
Exercises (13)
Sources
- Kinesiology of the Musculoskeletal System: Foundations for Rehabilitation — Biomechanics of Thoracic Extension