📖 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.
Cervical Extension
Cervical Intervertebral Joints (C2-C7) • Cervical Spine • sagittal plane
Bending the neck backward, looking upward. Combined motion of C2-C7.
Axis: medial-lateral
Normal Range of Motion
Whole-cervical extension from neutral using universal goniometer per AAOS/Norkin & White (0-45 deg). This is composite motion of the cervical spine, not isolated to C2-C7. CROM device and AMA Guides report higher values (up to 0-75-85 deg); considerable variability across instruments and with age.
Source: AAOS Joint Motion: Method of Measuring and Recording
Muscles (7)
| Muscle | Role | Notes |
|---|---|---|
| Semispinalis Capitis | Primary | Greatest force-generating capacity |
| Semispinalis Cervicis | Primary | Greatest force-generating capacity |
| Splenius Capitis | Primary | — |
| Splenius Cervicis | Secondary | — |
| Upper Trapezius | Secondary | — |
| Erector Spinae Group | Secondary | Cervical portion (longissimus cervicis) |
| Multifidus | Stabilizer | Cervical multifidus — segmental stabilizer |
Functional Tasks (1)
Exercises (6)
Sources
- Kinesiology of the Musculoskeletal System: Foundations for Rehabilitation — Biomechanics of Cervical Extension