The neck muscles (cervical muscles)

Cervical Muscles: Anatomy, Function, and Clinical Relevance

Introduction

The neck, or cervical region is a critically important area of anatomy because it supports the head, provides spanning movement, and protects the neurovascular structures. The cervical muscles contribute to posture, head movement, respiration and stabilize the cervical spine. The airflow of these muscles can be painful, grim, headache and limitation. Notifying the anatomy and clinical significance of them is important for physiotherapists, clinicians and students.

The cervical muscles can be broadly divided into superficial, intermediate, and deep groups, with each group performing specific functions.

1. Superficial Muscles

• Sternocleidomastoid (SCM):

  • Origin: Manubrium of sternum and medial third of clavicle

  • Insertion: Mastoid process of temporal bone and superior nuchal line

  • Nerve supply: Spinal accessory nerve (cranial nerve XI) and cervical plexus (C2–C3)

  • Function: Rotates head to opposite side, flexes neck, assists in forced inspiration.

• Trapezius (upper fibers):

  • Origin: External occipital protuberance, nuchal ligament

  • Insertion: Lateral third of clavicle, acromion, spine of scapula

  • Nerve supply: Spinal accessory nerve (CN XI)

  • Function: Elevates scapula, extends neck, assists in rotation.

2. Intermediate Muscles

• Scalenes (anterior, middle, posterior):

  • Origin: Transverse processes of cervical vertebrae (C2–C7)

  • Insertion: First and second ribs

  • Nerve supply: Ventral rami of cervical spinal nerves (C3–C8)

  • Function: Elevates first and second ribs (inspiration), flexes and laterally bends neck.

3. Deep Muscles

• Longus colli:

  • Origin: Bodies of cervical vertebrae C1–C6

  • Insertion: Vertebral bodies and transverse processes of cervical vertebrae

  • Nerve supply: Ventral rami of C2–C6

  • Function: Flexes neck, stabilizes cervical spine.

• Longus capitis:

  • Origin: Transverse processes of C3–C6

  • Insertion: Basilar part of occipital bone

  • Nerve supply: Ventral rami of C1–C3

  • Function: Flexes head and neck.

• Rectus capitis anterior and lateralis:

  • Provide fine control of head movement and stability.

• Suboccipital muscles (Rectus capitis posterior major/minor, Obliquus capitis superior/inferior):

  • Located deep at the base of the skull.

  • Function: Control small head movements, proprioception, and posture.

Functions of Cervical Muscles

1. Head and neck support and stabilization
2. Movements facilitated: flexion, extension, rotation & lateral flexion
3. Assistance in breathing (scalenes, SCM)
4. Supporting posture and stability of the cervical spine

Clinical Assessment

Palpation: Tightness, spasm, or tenderness in SCM, trapezius or scalenes.

ROM testing: To assess the movement and flexibility of cervical spine.

Strength testing: For neck flexors, extensors and rotators.

Special tests: employed with whiplash, cervical radiculopathy, or progressively increased instability.

Muscle conditions associated with the cervical region

• Cervical muscle strain or spasm – due to poor posture or sudden movements

• Cervicogenic headaches – often linked to suboccipital muscle tightness

• Whiplash injury – involves SCM and deep cervical flexors

• Torticollis (wry neck) – abnormal contraction of SCM causing head tilt

• Myofascial pain syndrome – trigger points in trapezius and scalenes

Exercises and Rehabilitation

• Strengthening: Isometric neck flexion, extension, and rotation exercises

• Stretching: SCM and upper trapezius stretches

• Postural training: Chin tucks, scapular stabilization exercises

• Manual therapy: Soft tissue release, joint mobilization

• Breathing exercises: Improve function of scalenes and accessory muscles

Conclusion

Cervical muscles are critical for head support, movement, posture and breathing. Failure of these muscles can be painful and debilitating. Knowledge of thier anatomy and clinical significance assists in accurate diagnosis, management and rehabiltation in physiotherapy treatment as well as medical practice.

FAQs

1. What are the main cervical muscles?
The major cervical muscles include sternocleidomastoid, trapezius, scalenes, longus colli, longus capitis, and suboccipital muscles.

2. Which cervical muscle is most commonly strained?
The sternocleidomastoid and trapezius are most often involved in strains due to posture or trauma.

3. How can I strengthen my cervical muscles?
Isometric neck exercises, chin tucks, and posture correction techniques are effective for strengthening.

4. What is the role of cervical muscles in headaches?
Tightness in suboccipital muscles and upper trapezius often contributes to tension-type or cervicogenic headaches.

5. Which nerve supplies most cervical muscles?
Most are supplied by cervical spinal nerves via ventral rami; some (like SCM and trapezius) are innervated by the spinal accessory nerve.