Lecture Notes: Neck Muscles

Major Neck Muscles

Sternocleidomastoid (SCM)

• Function: Works across the cervical spine.
• Structure: Comes in a pair (bilateral function).
• Movements:
  • Bilateral action: Extends the head at the cervical spine (C spine).
  • Unilateral action: Flexes the head or turns the head to the opposite side. For example, if turning head to the right, the left SCM contracts.

Deep Cervical Flexors

Longus Colli

• Function: Works with SCM.
• Movements:
  • Prevents hyperextension of the neck.
  • Holds the head in position for stable gaze.
  • Assists in tucking the chin (retraction of the neck).
• Importance: Particularly crucial for children with cerebral palsy who have difficulty with swallowing and eating. A stable head position helps with these activities.

Neck Extensors

Muscles Involved

• Spinalis Capitis

• Splenius Cervicis

• Function: Work with SCM for neck movements.

• Movements:

  • Bilateral action: Extends the neck.
  • Unilateral action: Rotates or bends the neck to the same side.

Summary

• SCM is the major muscle influencing head movement.
• Deep cervical flexors and neck extensors support various head and neck movements, contributing to stability and proper function, especially in individuals with neuromuscular challenges.