📖 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.
Extensor Digitorum
Common finger extensor. Extends the MCP joints of fingers 2-5.
Draft95%
Anatomy
- Origin
- Lateral epicondyle of humerus (common extensor origin)
- Insertion
- Extensor expansions of fingers 2-5
- Action
- Extension of MCP joints of fingers 2-5; assists wrist extension
- Innervation
- Posterior interosseous nerve (C7, C8)
- Blood Supply
- Posterior interosseous artery
Movements (5)
| Movement | Joint | Role | Notes |
|---|---|---|---|
| Finger Extension (MCP) | Metacarpophalangeal Joints | Primary | — |
| Finger Extension (PIP) | Proximal Interphalangeal Joints | Primary | Via extensor expansion |
| Wrist Extension | Radiocarpal Joint | Secondary | — |
| Finger Extension (DIP) | Distal Interphalangeal Joints | Secondary | Cannot fully extend DIP alone — requires intrinsic contribution [Murai 2012] |
| Finger Adduction (MCP) | Metacarpophalangeal Joints | Stabilizer | Maintains finger extension during adduction |
Exercises (17)
| Exercise | Role |
|---|---|
| Wrist Extensor Stretch | Primary |
| Finger Extension with Rubber Band | Primary |
| Tendon Gliding Exercises (Finger) | Primary |
| Median Nerve Glide | Primary |
| Ulnar Nerve Glide | Primary |
| Tyler Twist — Eccentric Wrist Extension (FlexBar) | Secondary |
| Intrinsic-Plus Position Hold | Secondary |
| Tendon Gliding Sequence | Secondary |
| Rubber-Band Finger Abduction | Stabilizer |
| Grip Strengthening (Squeeze Ball) | Stabilizer |
| Isolated Small-Finger Abduction | Stabilizer |
| Wrist Curls (Flexion/Extension) | Stabilizer |
| Wrist Circles (AROM) | Synergist |
| Wrist Neutral Splinting + Exercise Protocol (CTS) | Synergist |
| Nerve and Tendon Gliding Exercises (Carpal Tunnel) | Synergist |
| Radial Nerve Glide | lengthening |
| Desk Wrist Extensor Stretch | lengthening |
Sources
- Kinesiology of the Musculoskeletal System: Foundations for Rehabilitation — Anatomy of Extensor Digitorum — origin, insertion, action, innervation
- Muscles: Testing and Function with Posture and Pain — Manual muscle testing for Extensor Digitorum