| A | B |
|---|
| Origin of the anterior scalenes | anterior transverse processes of c3 through c6 |
| insertion of the anterior scalenes | first rib |
| Origin of the middle scalenes | posterior transverse processes of c2 through c7 |
| Insertion of the middle scalenes | first rib |
| Origin of the posterior scalenes | posterior transverse processes of c5 and c6 |
| insertion of the posterior scalenes | 2nd rib |
| Actions of the scalenes (unilaterally) | laterally flex the head and neck to the same side and rotate the head and neck to the opposite side |
| Action of the scalenes (bilateral) | elevate the ribs during inhalation |
| Action of the anterior scalenes (bilaterally) | flex the head and neck |
| Origin of the sternocleidomastoid | sternum and clavicle |
| Insertion of the sternocleidomastoid | mastoid process of the temporal bone and the lateral occiput |
| Actions of the sternocleidomastoid (unilateral) | laterally flex the head and neck to the same side and rotate the head and neck to the opposite side |
| Action of the sternocleidomastoid (bilaterally) | flex the neck |
| Origin of the splenius group | ligamentum nuchae, spinous processes of C 7 through T 6 |
| Insertion of the splenius group | transverse processes of the upper cervical vertebrae and the mastoid process |
| Actionsof the splenius group (unilateral) | laterally flex the head and neck and rotate the head and neck to the same side |
| Action of the splenius group (bilaterally) | extend the head and neck |
| Origin of the levator scapula | transverse processes of C 1 though C 4 |
| Insertion of the levator scapula | superior angle of the scapula |
| Actions of the Levator scapula (unilateral) | elevate the scapula at the scapulothoracic joint laterallty flex and rotate the head and neck to the same side |
| Action of the levator scapula (bilaterally) | extend the head and neck |
