📖 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.
Knee External Rotation
Tibiofemoral Joint • Knee • transverse plane
Draft80%
External rotation of the tibia on the femur. Occurs primarily with the knee flexed. Biceps femoris is the primary external rotator.
Axis: longitudinal
Normal Range of Motion
AROM
0–40°
Active range
PROM
—
Passive range
Measured with the knee flexed to 90°.
Source: AAOS / Norkin & White
Muscles (2)
| Muscle | Role | Notes |
|---|---|---|
| Biceps Femoris — Long Head | Primary | Moment arm at 30° flexion: 18.5-31.5 mm |
| Biceps Femoris — Short Head | Primary | Moment arm at 30° flexion: 14.7-27.9 mm |
Sources
- Kinesiology of the Musculoskeletal System: Foundations for Rehabilitation — Biomechanics of Knee External Rotation