238
PART 2 The Skeletal Muscles of the Upper Extremity
Thenar Eminence Group
■ ORGANIZATION OF THE
THENAR MUSCLES
■ MISCELLANEOUS
The thenar eminence is an eminence of soft tissue located on
the radial side of the palm of the hand. There are three muscles
in the thenar eminence group: the abductor pollicis brevis,
flexor pollicis brevis, and opponens pollicis.
The
■ ATTACHMENTS
All three thenar muscles attach proximally onto the flexor
9
retinaculum and carpal bones.
All three thenar muscles attach distally onto the thumb.
The abductor pollicis brevis and the flexor pollicis brevis
attach onto the proximal phalanx of the thumb.
The opponens pollicis attaches onto the metacarpal of the
thumb.
layering of the thenar muscles is approximately as
follows: The abductor pollicis brevis is the most superficial
of the three. The flexor pollicis brevis is intermediate. The
opponens pollicis is the deepest of the three.
There are three muscles located in the hypothenar eminence
that are analogous to the thenar muscles. The three hypothenar muscles are the abductor digiti minimi manus, flexor
digiti minimi manus, and opponens digiti minimi.
The thenar muscles are located within the deep front arm
line myofascial meridian.
INNERVATION
The three thenar muscles are innervated by the median nerve.
(The ulnar nerve usually contributes to a small degree.)
ARTERIAL SUPPLY
■ FUNCTIONS
All three thenar muscles move the thumb.
In each case, the name of the muscle indicates its major joint
The three thenar muscles receive their arterial supply from the
radial artery.
action.
Transverse carpal
ligament (flexor
retinaculum)
Opponens pollicis
Abductor pollicis brevis
Flexor pollicis brevis
A
Figure 9-5 Anterior views of the right thenar group muscles. A, Superficial view.
CHAPTER 9 Intrinsic Muscles of the Finger Joints
Thenar Eminence Group—cont’d
239
APB (cut)
FPB (cut)
OP
FPB (cut)
APB (cut)
9
B
Figure 9-5, cont’d B, Deep view. The abductor pollicis brevis and flexor pollicis brevis have been cut.
APB, abductor pollicis brevis; FPB, flexor pollicis brevis; OP, opponens pollicis.
CHAPTER 10 Muscles of the Spinal Joints
273
Anterior Views of the Muscles of the Trunk—Deep Views
6th rib
10
Internal
intercostals
Rectus abdominis
External abdominal
oblique (cut)
Diaphragm
Quadratus
lumborum
Psoas minor
Internal abdominal
oblique (cut)
Psoas major
Transversus
abdominis
Iliacus
Anterior superior
iliac spine (ASIS)
Inguinal ligament
Pyramidalis
B
Figure 10-2, cont’d B, Deep views with the posterior abdominal wall seen on the left. The muscles
of the neck, arm, and thigh have been ghosted in.
310
PART 3 The Skeletal Muscles of the Axial Body
NECK AND HEAD
Sternocleidomastoid (SCM)
The name, sternocleidomastoid, tells us that this muscle attaches
to the sternum, the clavicle, and the mastoid process of the temporal
bone.
Derivation
sterno:
Pronunciation
Gr. refers to the sternum.
cleido: Gr. refers to the clavicle.
mastoid: Gr. refers to the mastoid
process.
STER-no-KLI-do-MAS-toyd
■ ATTACHMENTS
STERNAL HEAD: Manubrium of the Sternum
the anterior superior surface
Medial Clavicle
Clavicular Head:
the medial 1 3
to the
10
Mastoid Process of the Temporal Bone
and the lateral 1 2 of the superior nuchal line of the occipi-
Trapezius
Sternal head
Clavicular head
tal bone
■ FUNCTIONS
Concentric (Shortening) Mover Actions
Standard Mover Actions
1. Flexes the lower neck at
the spinal joints
2. Extends the upper neck
and head at the spinal joints
3. Laterally flexes the neck
and head at the spinal joints
4. Contralaterally rotates the
neck and head at the spinal
joints
Reverse Mover Actions
1. Elevates the sternum and
trapezius has been ghosted in.
clavicle
Figure 10-19 Lateral view of the right sternocleidomastoid. The
2. Ipsilaterally rotates the trunk at
the spinal joints
Standard Mover Action Notes
• The sternocleidomastoid (SCM) crosses the joints of the
lower neck anteriorly (with its fibers running vertically in
the sagittal plane); therefore it flexes the lower neck at the
cervical spinal joints. (action 1)
• Because the SCM courses posteriorly as it ascends from the
sternum/clavicle to the head, it crosses the joints of the
upper neck posteriorly. Therefore, it extends the upper neck
at the cervical spinal joints and extends the head at the
atlanto-occipital joint (AOJ). (action 2)
• The SCM is the only muscle that can flex one region of the
neck and extend another region (every other muscle either
flexes or extends the neck). Exactly where the dividing line
is located is determined by the degree of curvature of the
client’s neck. (actions 1, 2)
• The SCM crosses the spinal joints laterally (with its fibers
running vertically in the frontal plane); therefore it laterally
flexes the neck at the cervical spinal joints and laterally flexes
the head at the AOJ. (action 3)
• The clavicular head is more active than the sternal head with
lateral flexion of the neck and head. (action 3)
• The SCM wraps around the neck from the sternum/clavicle
anteriorly to the cranium more posteriorly (with its fibers
running somewhat horizontally in the transverse plane).
When the SCM contracts, it pulls on the cranium, causing
the anterior surface of the neck and/or the head to face the
opposite side of the body from the side to which it is attached.
Therefore the SCM contralaterally rotates the neck at the
cervical spinal joints and the head at the AOJ. (action 4)
• The sternal head is more active than the clavicular head with
contralateral rotation of the neck and head. (action 4)
Reverse Mover Action Notes
• If the cranial attachment of the SCM is fixed, the sternal/
clavicular attachment must move. Because the SCM has its
fibers running vertically from the sternum/clavicle, the
sternum and the clavicle would be elevated toward the
cranial attachment. Elevating the sternum and clavicle can
assist in lifting the rib cage during inspiration (breathing in).
Therefore the SCM is an accessory muscle of respiration.
(reverse action 1)
CHAPTER 10 Muscles of the Spinal Joints
311
Sternocleidomastoid (SCM)—cont’d
• With the cranial attachment of the SCM fixed, the sternal/
clavicular attachment will be pulled in the transverse plane
such that the anterior surface of the trunk will come to face
the same side of the body to which the SCM is attached.
Therefore the SCM can ipsilaterally rotate the trunk at the
spinal joints (the reverse action of contralateral rotation of
the upper spine relative to the fixed lower spine is ipsilateral
rotation of the lower spine relative to the fixed upper spine).
This reverse action requires the cranial attachment to be
sufficiently fixed so that the weight of the trunk is moved
relative to it. (reverse action 2)
Eccentric Antagonist Functions
1. Restrains/slows extension of the lower neck at the spinal
joints
2. Restrains/slows flexion of the upper neck and head at the
spinal joints
3. Restrains/slows opposite-side lateral flexion and ipsilateral
rotation of the neck and head at the spinal joints
4. Restrains/slows depression of the sternum and clavicle
5. Restrains/slows ipsilateral rotation of the trunk
Isometric Stabilization Functions
1. Stabilizes the cervical spinal joints and the sternoclavicular
joint
Isometric Stabilization Function Note
• The SCM stabilizes the entire neck, including the head at
the AOJ. By attaching to the sternum and clavicle, it also
helps to stabilize the sternoclavicular joint.
Additional Notes on Functions
1. Some sources state that the action of the SCM on the head
at the AOJ can change from extension to flexion if the position of the head changes sufficiently, thus changing the line
of pull of the SCM relative to the AOJ. This becomes more
likely as a person ages and tends to posturally carry the head
more anteriorly.
2. The SCM may also be able to weakly upwardly rotate the
clavicle at the sternoclavicular joint.
INNERVATION
Spinal Accessory Nerve (CN XI)
and C2, C3
ARTERIAL SUPPLY
The Occipital and Posterior Auricular Arteries (branches of the
External Carotid Artery)
and the Superior Thyroid Artery (a branch of the External
Carotid Artery)
,
PA LPA TI ON
1. Have the client supine with the neck and head rotated
contralaterally.
2. Then have the client lift the head and neck up into the air and
the SCM will visibly contract.
3. Palpate the SCM from attachment to attachment.
■ RELATIONSHIP TO
OTHER STRUCTURES
Except for the platysma (which is superficial to all anterior
neck muscles), the SCM is superficial throughout its entire
course.
The following muscles are deep to the SCM (listed from
inferior to superior): infrahyoids, scalenes, levator scapulae,
digastric, and splenius capitis.
The attachment of the SCM onto the mastoid process of the
temporal bone and the superior nuchal line of the occipital
bone is superficial to the splenius capitis and lateral to the
trapezius.
The SCM is located within the superficial front line and
lateral line myofascial meridians.
■ MISCELLANEOUS
1. The SCM’s major superior attachment is the mastoid process
attachment of the temporal bone. However, it also has a thin
aponeurotic attachment to the occipital bone.
2. The carotid sinus of the common carotid artery lies directly
deep and medial to the SCM, midway up the neck. Given
the neurologic reflex that occurs to lower blood pressure
when the carotid sinus is pressed, massage to this region
must be done judiciously, especially with weak and/or elderly
clients.
3. The SCM and the scalenes, are often injured as a result of
car accidents. This trauma is usually called whiplash, wherein
the head and neck are forcefully thrown anteriorly and posteriorly (like a whip being lashed). When the head and the
neck are thrown posteriorly, the anterior cervical musculature may be torn; or the muscle spindle reflex may occur,
causing the anterior cervical musculature to spasm. When
the head and the neck are thrown anteriorly, the same
trauma may occur to the posterior musculature.
4. The SCM is an excellent landmark for palpating other
muscles of the neck. Locate the posterior (lateral) border
of the SCM and the anterior border of the upper trapezius,
and then palpate in the tall narrow triangular space that is
located between them; this triangular area is called the
posterior triangle of the neck. Locating the medial border of
the SCM can be used as a landmark for palpating the
longus colli and longus capitis (of the prevertebral group).
10
396
PART 3 The Skeletal Muscles of the Axial Body
Views of the Major Muscles of Mastication
Temporalis
Masseter
Figure 12-2 Right lateral view of the temporalis and masseter. The masseter has been ghosted in.
12
Lateral pterygoid
plate of sphenoid
Lateral
pterygoid
Mandibular
condyle
Superior
head
Superior
head
Inferior
head
Inferior
head
Maxilla
Medial
pterygoid
Medial
pterygoid
Angle of
mandible
Mandible
(cut)
Mandible
Figure 12-3 Views of the right lateral and medial pterygoids. A, Lateral view with the mandible
partially cut away. B, Posterior view of the lateral and medial pterygoids with the cranial bones cut away.
Lateral
pterygoid
398
PART 3 The Skeletal Muscles of the Axial Body
Temporalis
The name, temporalis, tells us that this muscle attaches onto the
temporal bone.
Derivation
Pronunciation
temporalis: L. refers to the temple.
tem-po-RA-lis
■ ATTACHMENTS
Temporal Fossa
the entire temporal fossa except the portion on the zygomatic bone
to the
Coronoid Process and the Ramus of the Mandible
the anterior border, apex, posterior border, and internal
surface of the coronoid process of the mandible, as
well as the anterior border of the ramus of the
mandible
Figure 12-5 Lateral view of the right temporalis. The masseter has
been ghosted in.
■ FUNCTIONS
12
Eccentric Antagonist Functions
CONCENTRIC (SHORTENING) MOVER ACTIONS
Standard Mover Actions
1. Elevates the mandible at
the TMJs
2. Retracts the mandible at the
TMJs
Reverse Mover Actions
1. Moves the temporal bone
inferiorly toward the mandible
2. Moves the temporal bone
anteriorly toward the mandible
TMJs = temporomandibular joints
Standard Mover Action Notes
• The anterior fibers of the temporalis are oriented vertically
from the cranium superiorly, to the mandible inferiorly.
When the temporalis contracts, it pulls the mandible superiorly toward the cranium. Therefore the temporalis elevates
the mandible at the TMJs. (action 1)
• The posterior fibers of the temporalis are oriented horizontally from the cranium posteriorly, to the mandible anteriorly. When the temporalis contracts, it pulls the mandible
posteriorly toward the cranium. Therefore the temporalis
retracts the mandible at the TMJs. (action 2)
Reverse Mover Action Notes
• Reverse actions of moving the temporal bone toward the
mandible require the mandible to be fixed and the temporal
bone and entire cranium to move toward the fixed mandible
at the TMJs. These reverse actions do not commonly occur.
When they do occur, they would be opposite in direction to
the standard mover actions. Therefore, the cranium would
be pulled inferiorly and anteriorly. (reverse actions 1, 2)
1. Restrains/slows depression and protraction of the mandible
Isometric Stabilization Function
1. Stabilizes the mandible at the TMJs
Additional Note on Functions
1. Some sources state that the temporalis also contributes to
side-to-side grinding by doing ipsilateral deviation of the
mandible at the TMJs.
INNERVATION
The Trigeminal Nerve (CN V)
deep temporal branches of the anterior trunk of the mandibular division of the trigeminal nerve
ARTERIAL SUPPLY
The Maxillary and Superficial Temporal Arteries (branches of
the External Carotid Artery)
,
PA LPA TI ON
1. With the client supine, place palpating fingers over the temporal
fossa.
2. Have the client alternately clench and relax the teeth and feel
for the contraction and relaxation of the temporalis. In this
manner the majority of the temporalis superior to the zygomatic
arch can be easily palpated.
CHAPTER 12 Muscles of the Temporomandibular Joints
399
Temporalis—cont’d
■ RELATIONSHIP TO OTHER
STRUCTURES
The superior portion of the temporalis is superficial (except
for the auriculares anterior and superior, which are superficial to it). The inferior portion of the temporalis runs deep
to the zygomatic arch. Inferior to the zygomatic arch, the
temporalis is deep to the masseter.
Deep to the superior portion of the temporalis are the cranial
bones (frontal, parietal, temporal, and sphenoid).
Deep to the inferior portion of the temporalis are the lateral
pterygoid, the superficial head of the medial pterygoid, and
a small part of the buccinator.
The temporalis is involved with the deep front line myofascial meridian.
■ MISCELLANEOUS
1. The temporalis muscle is deep to thick fibrous fascia called
the temporalis fascia.
2. The more superficial fibers of the temporalis actually attach
into the temporal fascia.
3. A tight temporalis may be involved with tension headaches
and with dysfunction of the temporomandibular joint (TMJ
syndrome).
4. The temporal fossa is a fossa (depression) that overlies not
only the temporal bone but also the frontal, parietal, zygomatic, and sphenoid bones.
5. The superficial temporal artery is superficial to the temporalis muscle, and its pulse can be palpated.
6. The temporal fossa is much deeper in carnivores, allowing
for a much thicker and stronger temporalis muscle. This
contributes to the strength of a carnivore’s bite.
12
430
PART 3 The Skeletal Muscles of the Axial Body
SCALP
Occipitofrontalis (of Epicranius)
The name, occipitofrontalis, tells us that this muscle lies over the
occipital and frontal bones.
Galea aponeurotica
Frontalis
Derivation
Pronunciation
occipitofrontalis: L. refers to the
occiput and the
frontal bone.
ok-SIP-i-to-fron-TA-lis
Occipitalis
■ ATTACHMENTS
OCCIPITALIS:
and the Temporal Bone
Occipital Bone
the lateral 2 3 of the highest nuchal line of the occipital
bone and the mastoid area of the temporal bone
Trapezius
Sternocleidomastoid
to the
Galea Aponeurotica
13
FRONTALIS:
Galea Aponeurotica
to the
A
Fascia and Skin overlying the Frontal Bone
■ FUNCTIONS
Concentric Mover Actions
1. Draws the Scalp Posteriorly (Elevation of the Eyebrow)
2. Draws the Scalp Anteriorly
Mover Action Notes
1. The occipitofrontalis attaches from the occipital and temporal bones posteriorly, to the fascia and skin overlying the
frontal bone anteriorly. The posterior attachment, which is
bone, is more fixed than the anterior attachment, which is
soft tissue. Therefore when the posterior attachment is fixed,
and the occipitofrontalis contracts, it pulls the anterior
attachment toward the posterior attachment. When this
occurs, the entire scalp moves posteriorly. This pulls on the
fascia and skin located superior to the eye, causing the
eyebrow to elevate and the skin of the forehead to wrinkle.
(action 1)
2. The frontalis belly of the occipitofrontalis attaches from
the fascia and skin overlying the frontal bone to the galea
aponeurotica posteriorly. When the anterior attachment is
fixed and the frontalis contracts, it pulls the posterior attachment (the galea aponeurotica) toward the anterior attachment. Therefore the scalp is drawn anteriorly. When this
occurs, the skin of the forehead may also wrinkle. (action 2)
B
Figure 13-5 The occipitofrontalis. A, Lateral view of the right occipitofrontalis. The trapezius and sternocleidomastoid have been ghosted
in. B, Expression of elevating the eyebrows created by the bilateral
contraction of the occipitofrontalis.
CHAPTER 13 Muscles of Facial Expression
431
Occipitofrontalis (of Epicranius)—cont’d
INNERVATION
The Facial Nerve (CN VII)
occipitalis: posterior auricular branch of the facial nerve
frontalis: temporal branches of the facial nerve
ARTERIAL SUPPLY
Occipitalis:
the Occipital and Posterior Auricular Arteries
(branches of the External Carotid Artery)
Frontalis: supraorbital and supratrochlear branches of the
Ophthalmic Artery (a branch of the Internal Carotid Artery)
,
P A L PATION
1. With the client prone or supine, place palpating hand over the
occipital bone and feel for the occipitalis, over the parietal bone
and feel for the galea aponeurotica, and over the frontal bone
and feel for the frontalis.
2. Ask the client to wrinkle the skin of the forehead, and feel for
the contraction of the muscle.
■ RELATIONSHIP TO OTHER
STRUCTURES
The
occipitalis is directly superior to the most superficial
muscles of the neck that attach into the superior nuchal line
and the mastoid process, namely, the trapezius and the
sternocleidomastoid.
The frontalis is superior to and even blends into the procerus, the corrugator supercilii, and the orbicularis oculi.
Lateral to the frontalis and the galea aponeurotica is the
temporoparietalis, and deep to that, the temporalis.
The occipitofrontalis is located within the superficial back
line myofascial meridian.
■ MISCELLANEOUS
1. The occipitofrontalis attaches into the galea aponeurotica;
the temporoparietalis also attaches into the galea aponeurotica. The occipitofrontalis and the temporoparietalis together
are known as the epicranius. (Note: The galea aponeurotica
is also known as the epicranial aponeurosis.)
2. The occipitofrontalis can be considered to be two separate
muscles: the occipitalis and the frontalis.
3. Elevation of the eyebrows often accompanies glancing
upward. Elevation of the eyebrows is associated with the
expressions of surprise, shock, horror, fright, or
recognition.
4. The occipitofrontalis is located within the scalp. The scalp
consists of five layers: the skin, subcutaneous tissue, the
epicranius and its aponeurosis (the galea aponeurotica),
loose connective tissue, and the pericranium. Of these layers,
the skin, the subcutaneous tissue, and the galea aponeurotica
are firmly connected to each other.
5. The left and right frontalis muscles blend into each other in
the midline of the head. The left and right occipitalis muscles
usually have a gap between them that is filled in with an
extension of the galea aponeurotica.
6. The occipitofrontalis is often ignored or only worked lightly
during bodywork. It is a muscle like any other in the body,
and moderate or even deeper work may be done to benefit
the client. Because tension headaches often involve the
occipitofrontalis, this muscle should be evaluated in any
client complaining of headaches, especially tension
headaches.
13
CHAPTER 14 Muscles of the Hip Joint
475
Posterior Views of the Muscles of the Hip Joint—Superficial and Intermediate Views
Iliac crest
Gluteus medius
Gluteus medius
(deep to fascia)
Sacrotuberous ligament
Piriformis
Tensor fasciae
latae
Superior gemellus
Obturator internus
Inferior gemellus
Sciatic nerve
Gluteus maximus
Greater trochanter of femur
Quadratus femoris
Ischial tuberosity
Adductor magnus
Iliotibial band (ITB)
Vastus lateralis
Vastus lateralis
Adductor magnus
Gracilis
14
Long head
Semitendinosus
Biceps femoris
Short head
Biceps femoris
Semimembranosus
Popliteal artery
and vein
Tibial nerve
Plantaris
Common fibular nerve
Sartorius
A
Figure 14-2 Posterior views of the muscles of the hip joint. A, Superficial view on the left and intermediate view on the right.