📖 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.
Thumb Flexion (MCP)
Thumb Metacarpophalangeal Joint • Hand • sagittal plane
Bending the thumb at the metacarpophalangeal joint.
Axis: medial-lateral
Normal Range of Motion
AAOS and Norkin & White list thumb MCP flexion as 0-50 degrees; the AMA Guides cite 0-60 degrees. Thumb MCP flexion is highly variable between individuals (reported normals span roughly 40-70 degrees).
Source: AAOS Joint Motion
Muscles (3)
| Muscle | Role | Notes |
|---|---|---|
| Flexor Pollicis Brevis | Primary | — |
| Flexor Pollicis Longus | Secondary | Also crosses MCP |
| Adductor Pollicis | Synergist | — |
Exercises (3)
Sources
- Kinesiology of the Musculoskeletal System: Foundations for Rehabilitation — Biomechanics of Thumb Flexion (MCP)