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Table 3-2. Actions of muscles which may restrict movement of cervical spine

MUSCLE	ACTION
rectus capitis dorsalis major	Unilateral Action: Dorsal flexes, rotates and laterally flexes the occiput and the atlas to the same side. Bilateral Action: Dorsal flex the occiput and the atlas.
rectus capitis dorsalis minor	Unilateral Action: Dorsal flexes, rotates and laterally flexes the occiput to the same side. (In ventral flexion, it may laterally flex to the same side and rotates to the opposite side). Bilateral Action: Dorsal flex occiput.
obliquus capitis superior head	Dorsal flexes the occiput while rotating to one side and laterally flexing to the opposite side.
inferior head	Dorsal flexes and rotates the atlas on the axis to the same side.
splenius capitis	Dorsal flexes and rotates the occiput to the same side.
splenius cendcis	Dorsal flexes, laterally flexes and rotates to the same side.
spinalis cendcis	Dorsal flexes, laterally flexes and rotates to the same side.
iliocostalis cendcis, longissi-mus cenicis, longissimus capitis	Dorsal flex, laterally flex and rotate cenical spine to same side.
semispinalis capitis	Dorsal flexes and slightly rotates the occiput to the opposite side.
trapezius descending part	Elevates the shoulder with the head and neck stabilized. Laterally flexes to one side and rotates the head and neck to the opposite side with the shoulder stabilized. Dorsal flexes the head when acting bilaterally.
interspinales	Dorsal flex the cervical spine
intertransversarii	Unilateral Action: Laterally flexes and rotates the cervical spine to the same side. Bilateral Action: Dorsal flex the cervical spine.
rotatores cervicis	Unilateral Action: Laterally flexes to one side: rotates to opposite side; dorsal flexes the cervical spine. Bilateral Action: Dorsal flex the cervical spine.
multifidi	Dorsal flex, laterally flex and rotate to the opposite side.
rectus capitis anterior lateralis	Ventral flexes the occiput on the atlas. Laterally flexes the occiput to the same side.
longus capitis	Ventral flexes, laterally flexes and rotates to the same side.
longus colli	Ventral flexes, laterally flexes and rotates to the same side.
suprahyoidales infrahyoidales platysma	Ventral flex while rotating and laterally flexing the occiput on the atlas to the same side (with the mouth closed).
sternocleidomastoideus	Unilateral Action: Ventral flexes the cervical spine while laterally flexing and rotating to opposite sides. Bilateral Action: (a) Dorsal flex the occiput on the atlas with the cervical spine stabilized in the mid-position. (b) Ventral flex the cervical spine with the cervical spine stabilized in the mid-position and with the occiput and the atlas ventrally flexed. (c) Act as an accessory muscle of respiration with the head and cervical spine stabilized.
scalenus anterior medius	Unilateral Action: Ventral flexes the cervical spine while laterally flexing and rotating to opposite sides. Bilateral Action: Ventral flex the cervical spine. Act as accessory muscles of respiration when the cervical spine is stabilized.
posterior	Unilateral Action: Rotates and laterally flexes to the same side. Bilateral Action: Dorsal flex the cervical spine.
subclavius	Depresses and stabilizes the clavicle during movements of the shoulder. Lifts the first rib when the shoulder is stabilized.

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