📖 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 Flexion
Tibiofemoral Joint • Knee • sagittal plane
Bending the knee, decreasing the angle between the leg and thigh.
Axis: medial-lateral
Normal Range of Motion
Measured supine or prone. AAOS lists 0-135 degrees; Norkin & White cite 0-140 (AAOS 1965 data also reports 143 as a mean). 135 is the most commonly used textbook norm; passive flexion with the hip flexed (soft-tissue approximation end feel) can reach approximately 140-150 degrees.
Source: AAOS Joint Motion
Muscles (10)
| Muscle | Role | Notes |
|---|---|---|
| Hamstrings (Group) | Primary | Group reference |
| Biceps Femoris — Long Head | Primary | — |
| Biceps Femoris — Short Head | Primary | — |
| Semitendinosus | Primary | — |
| Semimembranosus | Primary | — |
| Gastrocnemius | Secondary | — |
| Gracilis | Secondary | — |
| Sartorius | Secondary | — |
| Popliteus | Stabilizer | Dynamic stabilization and control |
| Plantaris | Synergist | Weak contribution |
Functional Tasks (4)
Exercises (42)
Sources
- Kinesiology of the Musculoskeletal System: Foundations for Rehabilitation — Biomechanics of Knee Flexion