Spinal nerve root
C1
Muscle contributions
Reported motor contributions, grouped by region. Muscles commonly receive more than one root; these groups are not a serial nerve pathway.
Posterior neck
- Rectus capitis posterior major
- Rectus capitis posterior minor
- Obliquus capitis superior
- Obliquus capitis inferior
Anterior neck
- Rectus capitis anterior
- Rectus capitis lateralis
- Longus capitis
Hyoid region
- Geniohyoid
- Thyrohyoid
- Sternohyoid
- Omohyoid
Source-dependent contributions
- Sternothyroid — C1 is included in some C1–C3 descriptions; others give C2–C3.
- Semispinalis capitis — C1 contribution is reported in some nerve descriptions; muscle-specific sources commonly give C2–C3.
Other deep posterior neck muscles have segmental posterior-ramus supply; the reviewed references do not resolve every muscle or fascicle to an individual root.