Anterior neck muscles

Question 1

Sternocleidomastoid (SCM)

Answer 1

Attachments: mastoid process + superior nuchal line –> sternum + clavicle
Actions:
- Unilateral: head extn (most fibres), ipsi head + neck lateral flexion, contra head + neck rotn
- Bilateral: head extn (most fibres), neck flexion (all fibres)

Question 2

Anterior scalene

Answer 2

Attachments: transverse processes of C3-C6 –> rib 1
Actions:
- Unilateral: neck lateral flexion, contra neck rotn
- Bilateral: neck flexion, elevation of rib 1
Functions: cervical spine stability

Question 3

Middle scalene

Answer 3

Attachments: transverse processes of C1 or C2-C7 –> rib 1
Actions:
- Unilateral: neck lateral flexion
- Bilateral: elevation of rib 1
Functions: cervical spine stability

Question 4

Posterior scalene

Answer 4

Attachments: transverse processes of C4-C6 –> rib 2
Actions:
- Unilateral: neck lateral flexion
- Bilateral: elevation of rib 2
Functions: cervical spine stability

Question 5

Infrahyoid muscles

Answer 5

Attachments:
- sternum + clavicle + scapula –> hyoid bone
- sternum + 1st cc –> thyroid cartilage –> hyoid bone
Actions:
- Uni/Bilateral: depress the hyoid bone
Functions: swallowing, speech