Movement Science Week 4 - Head and Neck Muscle Movements

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Questions and Answers

What action is produced by unilateral activation of the sternocleidomastoid muscle on one side?

Protraction of the cervical spine

Flexion of the contralateral cervical spine

Extension of the upper cervical spine only

Lateral flexion on the ipsilateral side and axial rotation on the contralateral side (correct)

During bilateral contraction of the sternocleidomastoid, what motion occurs in the upper cervical spine?

Lateral flexion

Flexion

Extension (correct)

Rotation

What do we call the combined motion of flexion in the mid to lower cervical spine and extension in the upper cervical spine?

Retraction

Lateral flexion

Protraction (correct)

Hyperextension

Which scalene muscles are involved in rib attachments?

All scalene muscles attach to the first and second ribs Signup and view all the answers

What is the function of the sternocleidomastoid muscle when activated bilaterally?

Results in extension of the upper cervical spine and flexion of the lower cervical spine Signup and view all the answers

What is the primary action of the scalenes in most situations?

Elevation of the ribs Signup and view all the answers

What condition can result from hypertrophy of the scalene muscles?

Thoracic outlet syndrome Signup and view all the answers

Which muscle originates on the occipital bone and plays a role in stabilizing the spine?

Longus capitis Signup and view all the answers

What is a common result of poor activation of the sternocleidomastoid (SCM) in patients?

Increased neck pain Signup and view all the answers

What do the splenius cervicis and splenius capitis primarily help with when contracted bilaterally?

Cervical extension Signup and view all the answers

What anatomical structure passes between the anterior and middle scalene muscles?

Brachial plexus Signup and view all the answers

What role does the longus coli play in the cervical region?

Stabilizes the spine and assists with flexion Signup and view all the answers

What is the purpose of a longus coli nod in a clinical setting?

To help rebalance muscle activation in the neck Signup and view all the answers

Which muscles provide precise control in the craniocervical region?

Suboccipital muscles Signup and view all the answers

What is a sign of forward head posture in a patient?

Ear aligns more with the sternum than the shoulder Signup and view all the answers

Study Notes

Anterior and Lateral Cranial Cervical Region Muscles

Sternocleidomastoid (SCM): Originates on the mastoid process, inserts on the sternum and clavicle. Unilateral activation causes ipsilateral lateral flexion and contralateral axial rotation. Bilateral activation causes upper cervical extension and lower cervical flexion (protraction).
Scalene Muscles (anterior, middle, posterior): Originate on transverse processes, attach to the first and second ribs. Primarily elevate ribs aiding ventilation. Can assist with cervical flexion if ribs are fixed. Hyperactivity can cause thoracic outlet syndrome by compressing the brachial plexus.
Longus Coli and Longus Capitis: Deep muscles stabilizing the spine and assisting with cervical flexion. Longus coli originates from C3-T3, inserts along the cervical vertebrae. Longus capitis originates on the occiput, inserts on the transverse processes of the mid-lower cervical spine. A longus coli nod, a therapeutic exercise involving chin tuck, can improve activation and reduce forward head posture.

Posterior Cranial Cervical Region Muscles

Splenius Muscles (cervicis and capitis): Splenius capitis originates on the occiput, inserts on the spinous processes of C7-T2. Splenius cervicis originates on the transverse processes of upper cervical vertebrae, inserts on the spinous processes of T2-T6. Unilateral contraction causes ipsilateral lateral flexion and rotation; bilateral contraction causes upper craniocervical extension.
Suboccipital Muscles: Small muscles spanning between the atlas and axis (AO and AA joints), providing fine motor control for head and eye movement, balance and coordination.

Craniocervical Stabilization and Posture

Forward Head Posture: Characterized by the ear being aligned with the sternum rather than the shoulder. This puts pressure on posterior muscles like the semispinalis capitis and levator scapulae. These muscles act as "guy wires," stabilizing the craniocervical region.
Causes of Forward Head Posture: Motor vehicle accidents (causing SCM and scalene muscle spasm), poor ergonomics (prolonged looking down at screens).
Consequences of Forward Head Posture: Suboccipital headaches, scalp pain, temporomandibular joint (TMJ) syndrome.

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Description

This quiz covers the anatomy and functions of the anterior and lateral cranial cervical region muscles, including the Sternocleidomastoid, Scalene muscles, Longus Coli, and Longus Capitis. Explore their origins, insertions, actions, and clinical considerations for a comprehensive understanding of these key muscles.