📖 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.
FHIR resources are build-time snapshots served as static files, not the live /api/exercises/<slug>/fhir route.
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

Draft80%

Extension of the thoracic spine. Often limited by kyphosis and rib cage. Critical for overhead reaching.

Axis: medial-lateral

Normal Range of Motion

AROM

0–25°

Active range

PROM

—

Passive range

Thoracic-region contribution; AAOS standardises the thoracolumbar region combined.

Source: Regional estimate

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