Transcript Muscles of the Posterior Neck

Myology
Muscles of the
Posterior Neck
1
Muscles of Neck Overview
• Miscellaneous
– Care must be taken when palpating anterior neck
musculature.
• The carotid sinus of the common carotid, if compressed,
can cause a neurological reflex that decrease heart rate.
This is especially important with weak and/or elderly
clients.
• The trachea, laryngeal cartilages, and thyroid gland are
delicate.
• Transverse processes (TP's) are bony and may cause
discomfort if soft tissue is compressed into them.
2
Muscles of Neck Overview
• Innervation
– Trapezius and sternocleidomastoid (SCM) are both
innervated by spinal accessory nerve (CN XI).
– Suboccipitals are innervated by suboccipital nerve.
– Scalenes, prevertebrals, and splenius capitis/cervicis are
innervated by cervical spinal nerves.
– Platysma is involved with facial expression and therefore
innervated by the facial nerve (CN VII).
– Infrahyoids innervated by cervical nerves.
– Suprahyoids innervated by cranial nerves.
3
Muscles of the Posterior Neck –
Superficial (4)
• Trapezius:
–Name tells us the left and right trap together have a
trapezoid shape (diamond shape).
–Entire trap is superficial in neck and also in the back
–Directly deep to trap in neck are semispinalis capitis,
splenius capitis & levator scapulae.
–Directly deep to trapezius in trunk are rhomboids and
superior part of latissimus dorsi.
–Directly anterior to the anterior border of trap are levator
scapulae and scalenes.
–Considered to have three functional parts: upper (which
elevated the scapulae), middle (which adducts the scapulae),
and lower (which depress the scapulae).
4
Muscles of the Posterior Neck –
Superficial (4)
• Splenius Capitis:
–Shaped like a bandage (narrow rectangle) and attaches onto
the head
–Left & right splenius capitis muscles bilaterally form a “V”
shape; sometimes known as the “golf tee” muscles
• Splenius Cervicis:
–Left & right splenius capitis muscles bilaterally form a “V”
shape
• Levator Scapulae:
–At midpoint, there is a twist in the fibers that creates an
increased density which is often mistaken for a trigger point
(when present a levator scapulae trigger point is usually
located just superior to the angle of the scapula).
–Levator scapulae can also cause downward rotation of
glenohumeral joint.
5
Trapezius
O: EOP, Superior Nuchal Line, Nuchal ligament,
and the SP of C7 through T12
I: Upper Traps: Lateral 1/3 of clavicle & Acromion
Middle Traps: Spine of scapula and acromion
Lower Traps: Root of the Spine of the scapula
A: Upper Traps: Elevates, upwardly rotates, and
retracts the scapula
Middle Traps: Retracts the scapula
Lower Traps: Depresses, upwardly rotates, and
retracts the scapula
**Reversed muscle action: Bilaterally allows
for extension of the neck. Unilaterally laterally
flexes the neck to the same side and rotates to the
opposite side.
N: CN XI (Spinal accessory nerve) and posterior
rami of C3 and C4
Palpation: Page 111
6
Splenius Capitis
O: Nuchal ligament and the SP’s
of C7-T4
I: Mastoid process and the occiput
A: Bilateral contraction:
Extension of the neck
Unilateral contraction: Lateral
flexion and Ipsilateral rotation
of the neck
N: posterior rami of the cervical
spinal nerves
Palpation: Page 115
7
Splenius Cervicis
O: SP’s of T4 – T6
I: TP’s of C1 – C3
A: Bilateral contraction:
Extension of the neck
Unilateral contraction: Lateral
flexion and Ipsilateral rotation
of the neck
N: posterior rami of the cervical
spinal nerves
Palpation: Page 118
8
Levator Scapulae
O: TP’s of C1 – C4
I: Medial border of the scapula, from
the superior angle to the root of the
spine of the scapula
A: Elevates retracts, and downwardly
rotates scapula.
**Reversed muscle action:
Bilaterally allows for extension of
the neck. Unilaterally laterally
flexes the neck to the same side
and rotates the to the same side.
N: Dorsal Scapular nerve
Palpation: Page 118
9
Muscles of the Posterior Neck – Deep
(Suboccipitals) (4)
• Suboccipitals are found deep to trap, SCM, splenius capitis, and
semispinalis capitis.
• Suboccipitals are more important as postural muscles, providing
fine control of head posture, than movers.
• Rectus Capitis Posterior Major:
– “rectus” means straight. Both rectus muscles run straight up
to inferior nuchal line of occiput.
– “capitis” refers to head
– “posterior” means toward back
– “major” means larger
• Rectus Capitis Posterior Minor:
– “minor” means smaller
• Obliquus Capitis Inferior:
– “obliquus” means slanted. Both obliquus muscles run in a
slanted fashion.
10
• Obliquus Capitis Superior
Rectus Capitis Posterior Major
O: SP of the Axis (C2)
I: Occiput (lateral aspect)
A: Bilateral contraction: Extension of
Head
Unilateral contraction: Lateral
flexion and Ipsilateral rotation of
neck
N: Suboccipital nerve
Palpation: Page 127
11
Rectus Capitis Posterior Minor
O: Posterior tubercle of the
Atlas (C1)
I: Occiput
A: Bilateral contraction will
cause Extension of Head
N: Suboccipital nerve
Palpation: Page 130
12
Obliquus Capitis Inferior
O: SP of the Axis (C2)
I: TP of the Atlas (C1)
A: Ipsilateral Rotation of
Atlas
N: Suboccipital nerve
Palpation: Page 132
13
Obliquus Capitis Superior
O: TP of the Atlas (C1)
I: Occiput (between the superior
and inferior nuchal lines)
A: Bilateral Contraction:
Extension of Head
Unilateral Contraction: Lateral
flexion of the head.
N: Suboccipital nerve
Palpation: Page 135
14
Suboccipital
Triangle
• Formed by RCPM, OCS, &
OCI, the suboccipital triangle is
covered by a layer of dense
fibro-fatty tissue, situated
beneath the Semispinalis
capitis.
• The floor is formed by the
posterior occipito-atlantal
membrane, and the posterior
arch of the atlas.
• In the deep groove on the upper
surface of the posterior arch of
the atlas are the vertebral artery
and the first cervical or
suboccipital nerve.
15