📖 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.
Finger Extension (MCP)
Metacarpophalangeal Joints • Hand • sagittal plane
Straightening the fingers at the metacarpophalangeal joints.
Axis: medial-lateral
Normal Range of Motion
MCP hyperextension beyond the 0-degree neutral: AAOS lists 45 degrees. Passive MCP hyperextension can considerably exceed active in lax individuals (up to ~90 passively per some sources).
Source: AAOS Joint Motion; Norkin & White 2016
Muscles (3)
| Muscle | Role | Notes |
|---|---|---|
| Extensor Digitorum | Primary | — |
| Lumbricals (Hand) | Synergist | Flex MCP while extending IP |
| Dorsal Interossei (Hand) | Synergist | Assist IP extension via lateral bands |
Functional Tasks (2)
Exercises (9)
Sources
- Kinesiology of the Musculoskeletal System: Foundations for Rehabilitation — Biomechanics of Finger Extension (MCP)