📖 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.
Sternocleidomastoid
Large superficial cervical muscle. Bilateral action flexes the neck; unilateral action rotates and laterally flexes.
Draft95%
Anatomy
- Origin
- Sternal head: manubrium; Clavicular head: medial third of clavicle
- Insertion
- Mastoid process, superior nuchal line
- Action
- Bilateral: cervical flexion; Unilateral: ipsilateral lateral flexion, contralateral rotation
- Innervation
- Cranial nerve XI (spinal accessory nerve) with contributions from C2-C3
- Blood Supply
- Superior thyroid artery, occipital artery, suprascapular artery
Movements (5)
| Movement | Joint | Role | Notes |
|---|---|---|---|
| Cervical Flexion | Cervical Intervertebral Joints (C2-C7) | Primary | Bilateral action |
| Cervical Lateral Flexion | Cervical Intervertebral Joints (C2-C7) | Primary | Ipsilateral; unilateral action |
| Cervical Rotation | Cervical Intervertebral Joints (C2-C7) | Primary | Contralateral rotation; dominant force producer |
| Upper Cervical Rotation | Atlantoaxial Joint | Secondary | Contralateral rotation |
| Upper Cervical Flexion | Atlantooccipital Joint | Synergist | Assists upper cervical flexion when DCFs active |
Exercises (13)
| Exercise | Role |
|---|---|
| Cervical Protraction Awareness | Primary |
| Seated Cervical Flexion AROM | Primary |
| Isometric Neck Strengthening (4 Directions) | Secondary |
| Upper Cervical Rotation Drill | Secondary |
| Deep Neck Flexor Training (Chin Tucks with Pressure Biofeedback) | Stabilizer |
| Upper Cervical (Suboccipital) Exercise with Release | Stabilizer |
| Sitting Craniocervical Flexion with Oblique Band Resistance | Stabilizer |
| Seated Trunk Rotation | Synergist |
| Crunch | Synergist |
| Sit-Up | Synergist |
| Supine Chin Tuck with Liftoff | Synergist |
| Cobra Pose | lengthening |
| Mindfulness-Integrated Stretching | lengthening |
Sources
- Kinesiology of the Musculoskeletal System: Foundations for Rehabilitation — Anatomy of Sternocleidomastoid — origin, insertion, action, innervation
- Muscles: Testing and Function with Posture and Pain — Manual muscle testing for Sternocleidomastoid