📖 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.
Knee Extension
Tibiofemoral Joint • Knee • sagittal plane
Straightening the knee, increasing the angle between the leg and thigh.
Axis: medial-lateral
Normal Range of Motion
Normal active end range is 0 degrees (full extension to anatomical neutral, i.e., the return from flexion). Up to about 10 degrees of passive hyperextension (recorded as recurvatum or negative extension) is considered within normal limits, more common in women and hypermobile individuals.
Source: AAOS Joint Motion; Norkin & White 2016
Muscles (8)
| Muscle | Role | Notes |
|---|---|---|
| Quadriceps Femoris | Primary | Group reference |
| Rectus Femoris | Primary | Two-joint component of quadriceps |
| Vastus Lateralis | Primary | Also acts as general joint stabilizer |
| Vastus Medialis | Primary | VMO contributes to medial patellar tracking |
| Vastus Intermedius | Primary | — |
| Erector Spinae Group | Stabilizer | Trunk stability during squatting |
| Transversus Abdominis | Stabilizer | Core stability during squatting |
| Gastrocnemius | Stabilizer | Eccentric role during knee extension |
Functional Tasks (9)
Exercises (53)
Sources
- Kinesiology of the Musculoskeletal System: Foundations for Rehabilitation — Biomechanics of Knee Extension