Download Muscles - 1 copy for web page

Skeletal Muscles: Functional Groups
1. Prime movers
•
Provide the major force for producing a
specific movement
2. Antagonists
•
Oppose or reverse a particular movement
Copyright © 2010 Pearson Education, Inc.
Skeletal Muscles: Functional Groups
3. Synergists
•
Add force to a movement
•
Reduce undesirable or unnecessary
movement
4. Fixators
•
Synergists that immobilize a bone or
muscle’s origin
Copyright © 2010 Pearson Education, Inc.
Naming Skeletal Muscles
1. Location —bone or body region associated with
the muscle
2. Shape —e.g., deltoid muscle (deltoid = triangle)
3. Relative size —e.g., maximus (largest), minimus
(smallest), longus (long)
4. Direction of fibers or fascicles —e.g., rectus
(fibers run straight), transversus, and oblique
(fibers run at angles to an imaginary defined axis)
Copyright © 2010 Pearson Education, Inc.
Naming Skeletal Muscles
5. Number of origins —e.g., biceps (2 origins) and
triceps (3 origins)
6. Location of attachments —named according to
point of origin or insertion
7. Action —e.g., flexor or extensor, muscles that
flex or extend, respectively
Copyright © 2010 Pearson Education, Inc.
Muscle Mechanics: Arrangement of Fascicles
1. Circular
• Fascicles arranged in concentric rings (e.g.,
orbicularis oris)
2. Convergent
• Fascicles converge toward a single tendon insertion
(e.g., pectoralis major)
Copyright © 2010 Pearson Education, Inc.
Muscle Mechanics: Arrangement of Fascicles
3. Parallel
• Fascicles parallel to the long axis of a straplike
muscle (e.g., sartorius)
4. Fusiform
• Spindle-shaped muscles with parallel fibers (e.g.,
biceps brachii)
5. Pennate
• Short fascicles attach obliquely to a central tendon
running the length of the muscle (e.g., rectus
femoris)
Copyright © 2010 Pearson Education, Inc.
(a)
(b)
(g)
(f)
Circular
(orbicularis oris)
(c)
(e)
(c) Parallel
(sartorius)
(d)
(e) Bipennate
(rectus femoris)
(f) Fusiform
(biceps brachii)
Copyright © 2010 Pearson Education, Inc.
(b) Convergent
(pectoralis major)
(d) Unipennate
(extensor
digitorum
longus)
(g) Multipennate
(deltoid)
Figure 10.1
Muscle Mechanics: Lever Systems
• Components of a lever system
• Lever —rigid bar (bone) that moves on a fixed
point or fulcrum (joint)
• Effort —force (supplied by muscle contraction)
applied to a lever to move a resistance (load)
• Load —resistance (bone + tissues + any
added weight) moved by the effort
Copyright © 2010 Pearson Education, Inc.
Effort x length of effort arm = load x length of load arm
(force x distance) = (resistance x distance)
Effort
10
kg
0.25 cm
Effort
25 cm
Fulcrum
10 x 25 = 1000 x 0.25
250 = 250
1000 kg
Load
Load
Fulcrum
(a) Mechanical advantage with a power lever
Copyright © 2010 Pearson Education, Inc.
Figure 10.2a
Effort
100 kg
Effort
Load
25 cm
50 cm
Fulcrum
Fulcrum
100 x 25 = 50 x 50
2500 = 2500
50 kg
Load
(b) Mechanical disadvantage with a speed lever
Copyright © 2010 Pearson Education, Inc.
Figure 10.2b
Classes of Lever Systems
• First class
• Fulcrum between load and effort
Copyright © 2010 Pearson Education, Inc.
(a) First-class lever
Arrangement of the elements is
load-fulcrum-effort
Load
Effort
Fulcrum
Load
Fulcrum
Effort
Example: scissors
Copyright © 2010 Pearson Education, Inc.
Figure 10.3a (1 of 2)
(a) First-class lever
Arrangement of the elements is
load-fulcrum-effort
Fulcrum
Load
Effort
In the body: A first-class lever system
raises your head off your chest. The
posterior neck muscles provide the effort,
the atlanto-occipital joint is the fulcrum,
and the weight to be lifted is the facial
skeleton.
Copyright © 2010 Pearson Education, Inc.
Figure 10.3a (2 of 2)
Classes of Lever Systems
• Second class
• Load between fulcrum and effort
Copyright © 2010 Pearson Education, Inc.
(b) Second-class lever
Arrangement of the elements is
fulcrum-load-effort
Load
Fulcrum
Effort
Load
Effort
Fulcrum
Copyright © 2010 Pearson Education, Inc.
Example: wheelbarrow
Figure 10.3b (1 of 2)
(b) Second-class lever
Arrangement of the elements is
fulcrum-load-effort
Effort
Load
Fulcrum
In the body: Second-class leverage is
exerted when you stand on tip-toe. The
effort is exerted by the calf muscles
pulling upward on the heel; the joints of
the ball of the foot are the fulcrum; and
the weight of the body is the load.
Copyright © 2010 Pearson Education, Inc.
Figure 10.3b (2 of 2)
Classes of Lever Systems
• Third class
• Effort applied between fulcrum and load
Copyright © 2010 Pearson Education, Inc.
(c) Third-class lever
Arrangement of the elements is
load-effort-fulcrum
Load
Effort
Fulcrum
Load
Fulcrum
Effort
Example: tweezers or forceps
Copyright © 2010 Pearson Education, Inc.
Figure 10.3c (1 of 2)
(c) Third-class lever
Arrangement of the elements is
load-effort-fulcrum
Effort
Load
Fulcrum
In the body: Flexing the forearm by the
biceps brachii muscle exemplifies
third-class leverage. The effort is exerted
on the proximal radius of the forearm, the
fulcrum is the elbow joint, and the load is
the hand and distal end of the forearm.
Copyright © 2010 Pearson Education, Inc.
Figure 10.3c (2 of 2)
Major Skeletal Muscles of the Body
• Grouped by function and location
• Information for each muscle
• Name and description —note information in the name
• Origin and insertion —there is usually a joint between the
origin and the insertion
• Action —insertion moves toward origin; best learned by
acting out muscle movement on one’s own body
• Innervation —name of major nerve that supplies the muscle
Copyright © 2010 Pearson Education, Inc.
Head
Temporalis
Masseter
Shoulder
Trapezius
Deltoid
Arm
Triceps brachii
Biceps brachii
Brachialis
Forearm
Pronator teres
Brachioradialis
Flexor carpi radialis
Palmaris longus
Pelvis/thigh
Iliopsoas
Pectineus
Thigh
Rectus femoris
Vastus lateralis
Vastus medialis
Leg
Fibularis longus
Extensor digitorum longus
Tibialis anterior
Copyright © 2010 Pearson Education, Inc.
Facial
Epicranius, frontal belly
Orbicularis oculi
Zygomaticus
Orbicularis oris
Neck
Sternohyoid
Platysma
Sternocleidomastoid
Thorax
Pectoralis minor
Serratus anterior
Pectoralis major
Intercostals
Abdomen
Rectus abdominis
Internal oblique
Transversus abdominis
External oblique
Thigh
Tensor fasciae latae
Sartorius
Adductor longus
Gracilis
Leg
Gastrocnemius
Soleus
Figure 10.4
Arm
Triceps brachii
Brachialis
Forearm
Brachioradialis
Extensor carpi
radialis longus
Flexor carpi ulnaris
Extensor carpi
ulnaris
Extensor digitorum
Iliotibial tract
Leg
Gastrocnemius
Soleus
Fibularis longus
Calcaneal
(Achilles) tendon
Copyright © 2010 Pearson Education, Inc.
Neck
Epicranius, occipital belly
Sternocleidomastoid
Trapezius
Shoulder
Deltoid
Infraspinatus
Teres major
Rhomboid major
Latissimus dorsi
Hip
Gluteus medius
Gluteus maximus
Thigh
Adductor magnus
Hamstrings:
Biceps femoris
Semitendinosus
Semimembranosus
Figure 10.5
Muscles of the Head
•
Two groups
1. Muscles of facial expression
2. Muscles of mastication and tongue
movement
Copyright © 2010 Pearson Education, Inc.
Muscles of Facial Expression
• Insert into the skin
• Important in nonverbal communication
• All innervated by cranial nerve VII (facial
nerve)
Copyright © 2010 Pearson Education, Inc.
Muscles of Facial Expression
• Epicranius (occipitofrontalis)
• Bipartite muscle consisting of the
• Frontalis
• Occipitalis
• Galea aponeurotica—cranial aponeurosis
connecting above muscles
• The two muscles have alternate actions of
pulling the scalp forward and backward
Copyright © 2010 Pearson Education, Inc.
Epicranius
Corrugator
supercilii
Orbicularis oculi
Levator labii
superioris
Zygomaticus
minor and major
Buccinator
Risorius
Orbicularis oris
Mentalis
Depressor
labii inferioris
Depressor anguli oris
Platysma
Copyright © 2010 Pearson Education, Inc.
Galea
aponeurotica
Frontal belly
Occipital
belly
Temporalis
Masseter
Sternocleidomastoid
Trapezius
Splenius capitis
Figure 10.6
Muscles of Mastication
• Four pairs involved in mastication
• Prime movers of jaw closure
• Temporalis and masseter
• Grinding movements
• Medial and lateral pterygoids
• All are innervated by cranial nerve V (trigeminal
nerve)
• Buccinator muscles (of facial expression group)
also help by holding food between the teeth
Copyright © 2010 Pearson Education, Inc.
Muscles Tongue Movement
• Three muscles anchor and move the tongue
• All are innervated by cranial nerve XII
(hypoglossal nerve)
Copyright © 2010 Pearson Education, Inc.
Temporalis
Orbicularis
oris
Buccinator
Masseter
(a)
Copyright © 2010 Pearson Education, Inc.
Figure 10.7a
Muscles of Mastication and Tongue
Movement
PLAY
A&P Flix™: Temporalis
PLAY
A&P Flix™: Masseter
PLAY
A&P Flix™: Buccinator
Copyright © 2010 Pearson Education, Inc.
Lateral
pterygoid
Medial
pterygoid
(b)
Copyright © 2010 Pearson Education, Inc.
Masseter
pulled away
Figure 10.7b
Tongue
Styloid process
Styloglossus
Hyoglossus
Stylohyoid
Hyoid bone
Genioglossus
Mandibular
symphysis
Geniohyoid
Thyroid cartilage
Copyright © 2010 Pearson Education, Inc.
Thyrohyoid
(c)
Figure 10.7c
Muscles of the Anterior Neck and Throat
• Most are involved in swallowing
• Two groups
1. Suprahyoid
2. Infrahyoid
Copyright © 2010 Pearson Education, Inc.
Suprahyoid Muscles of the Anterior Neck
and Throat
• Four deep muscles are involved in swallowing
(they move the hyoid bone and larynx)
• Form the floor of the oral cavity
• Anchor the tongue
• Move the hyoid bone and the larynx
Copyright © 2010 Pearson Education, Inc.
Infrahyoid Muscles of the Anterior Neck and
Throat
• Straplike muscles that depress the hyoid and
larynx as swallowing ends and during
speaking
Copyright © 2010 Pearson Education, Inc.
Median raphe
Anterior
Digastric belly
Posterior
belly
Stylohyoid (cut)
Thyrohyoid
Thyroid cartilage
of the larynx
Thyroid gland
Sternothyroid
Mylohyoid
Stylohyoid
Hyoid bone
Omohyoid
(superior belly)
Sternohyoid
Sternocleidomastoid
Omohyoid
(inferior belly)
(a)
Copyright © 2010 Pearson Education, Inc.
Figure 10.8a
Tensor veli palatini
Levator veli palatini
Styloid process
Superior pharyngeal
constrictor
Middle pharyngeal
constrictor
Hyoid bone
Thyrohyoid
membrane
Inferior
pharyngeal
constrictor
(c)
Esophagus
Copyright © 2010 Pearson Education, Inc.
Buccinator
Mandible
Mylohyoid
(cut)
Geniohyoid
Hyoglossus
Thyroid
cartilage
of larynx
Trachea
Figure 10.8c
Infrahyoid Muscles of the Anterior Neck and
Throat
PLAY
Animation: Rotating head
PLAY
Animation: Rotating face
Copyright © 2010 Pearson Education, Inc.
Muscles of the Neck and Vertebral Column
• Two functional groups
• Muscles that move the head
• Muscles that extend the trunk and maintain
posture
Copyright © 2010 Pearson Education, Inc.
Muscles of the Neck and Vertebral Column:
Head Movement
• Sternocleidomastoid—major head flexor
• Suprahyoid and infrahyoid—synergists to
head flexion
• Sternocleidomastoid and scalenes—lateral
head movements
• Semispinalis capitis—synergist with
sternocleidomastoid
• Splenius (capitis and cervicis portions): head
extension, rotation, and lateral bending
Copyright © 2010 Pearson Education, Inc.
1st cervical
vertebra
Sternocleidomastoid
Base of
occipital bone
Mastoid
process
Middle
scalene
Anterior
scalene
Posterior
scalene
(a) Anterior
Copyright © 2010 Pearson Education, Inc.
Figure 10.9a
Mastoid process
Splenius
capitis
Spinous
processes
of the
vertebrae
Splenius
cervicis
(b) Posterior
Copyright © 2010 Pearson Education, Inc.
Figure 10.9b
Muscles of the Neck and Vertebral Column:
Head Movement
PLAY
A&P Flix™: Splenius capitis
PLAY
A&P Flix™: Semispinalis capitis
Copyright © 2010 Pearson Education, Inc.
Muscles of the Neck and Vertebral Column:
Trunk Extension
• Deep (intrinsic) back muscles
• Erector spinae (sacrospinalis) group—prime
movers of back extension and lateral bending
• Iliocostalis
• Longissimus
• Spinalis
• Semispinalis and quadratus lumborum—
synergists in extension and rotation
Copyright © 2010 Pearson Education, Inc.
Mastoid process
of temporal bone
Longissimus capitis
Iliocostalis cervicis
Longissimus
cervicis
Iliocostalis
thoracis
Longissimus thoracis
Spinalis thoracis
Iliocostalis
Erector Longissimus
spinae Spinalis
Iliocostalis
lumborum
External oblique
Ligamentum
nuchae
Semispinalis
capitis
Semispinalis
cervicis
Semispinalis
thoracis
Multifidus
Quadratus
lumborum
(d)
Copyright © 2010 Pearson Education, Inc.
Figure 10.9d
Muscles of the Neck and Vertebral Column:
Trunk Extension
PLAY
A&P Flix™: Iliocostalis
PLAY
A&P Flix™: Longissimus
PLAY
A&P Flix™: Spinalis
Copyright © 2010 Pearson Education, Inc.
Muscles of the Thorax
• Muscles of respiration
1. External intercostals — more superficial muscles
that elevate ribs for inspiration
2. Internal intercostals — deeper muscles that aid
forced expiration
3. Diaphragm
• Partition between thoracic and abdominal cavities
• Most important muscle in inspiration
• Innervated by phrenic nerves
Copyright © 2010 Pearson Education, Inc.
External
intercostal
(a)
Copyright © 2010 Pearson Education, Inc.
Internal
intercostal
Figure 10.10a
Muscles of the Thorax
PLAY
A&P Flix™: External intercostals
PLAY
A&P Flix™: Internal intercostals
Copyright © 2010 Pearson Education, Inc.
Xiphoid process of sternum
Foramen for inferior
vena cava
Central
tendon of
diaphragm
Foramen
for aorta
12th rib
(b)
Copyright © 2010 Pearson Education, Inc.
Foramen for
esophagus
Costal cartilage
Diaphragm
Lumbar
vertebra
Quadratus
lumborum
Psoas major
Figure 10.10b
Muscles of the Abdominal Wall
• Four paired muscles; their fasciae and
aponeuroses form the lateral and anterior
abdominal wall
1. Internal obliques
2. External obliques
3. Transversus abdominis
4. Rectus abdominis
Copyright © 2010 Pearson Education, Inc.
Pectoralis major
Serratus anterior
Linea alba
Transversus abdominis
Internal oblique
External oblique
Aponeurosis of the
external oblique
(a)
Copyright © 2010 Pearson Education, Inc.
Tendinous
intersection
Rectus
abdominis
Inguinal ligament
(formed by free
inferior border of
the external oblique
aponeurosis)
Figure 10.11a
Muscles of the Abdominal Wall
• Fascicles of these muscles run at angles to
one another, providing added strength
• All are innervated by intercostal nerves
• Actions of these muscles
1. Lateral flexion and rotation of the trunk
2. Help promote urination, defecation, childbirth,
vomiting, coughing, and screaming
Copyright © 2010 Pearson Education, Inc.
Rectus
abdominis
Internal
oblique
External
oblique
IIiac crest
Pubic
tubercle
Transversus
abdominis
Inguinal
ligament
Lumbar
fascia
Lumbar
fascia
(b)
Copyright © 2010 Pearson Education, Inc.
Figure 10.11b
Muscles of the Abdominal Wall
PLAY
A&P Flix™: External obliques
PLAY
A&P Flix™: Internal obliques
PLAY
A&P Flix™: Rectus abdominis
PLAY
A&P Flix™: Transversus abdominis
Copyright © 2010 Pearson Education, Inc.
Muscles of the Pelvic Floor
• Pelvic floor (pelvic diaphragm) is composed of
two paired muscles
1. Levator ani
2. Coccygeus
• Both are innervated by sacral nerves
Copyright © 2010 Pearson Education, Inc.
Muscles of the Pelvic Floor
• Functions of the pelvic diaphragm
• Seals the inferior outlet of the pelvis
• Supports pelvic organs
• Lifts pelvic floor to help release feces
• Resists increased intra-abdominal pressure
Copyright © 2010 Pearson Education, Inc.
Muscles of the Perineum
• Urogenital diaphragm
• Anterior half of perineum, inferior to pelvic floor
1. Deep transverse perineal muscle
2. External urethral sphincter (voluntary control of
urination)
Copyright © 2010 Pearson Education, Inc.
Anterior
Levator
ani
Symphysis pubis
Urogenital diaphragm
Urethra
Vagina
Anal canal
Pubococcygeus
IIiococcygeus
Obturator
internus
Coccyx
Levator ani
Coccygeus
Piriformis
(a)
Copyright © 2010 Pearson Education, Inc.
Posterior
Pelvic
diaphragm
Figure 10.12a
Urethral
opening
External urethral
sphincter
Inferior pubic ramus
Deep
transverse
perineal
muscle
Central tendon
Vaginal
opening
Anus
External anal
sphincter
(b)
Male
Copyright © 2010 Pearson Education, Inc.
Female
Figure 10.12b
Muscles of the Perineum
• Muscles of superficial perineal space
1. Ischiocavernosus
2. Bulbospongiosus
3. Superficial transverse perineal muscles
• External anal sphincter (in posterior half of
perineum)
Copyright © 2010 Pearson Education, Inc.
Urethral
opening
Vaginal
opening
Clitoris
Anus
Penis
Midline raphe
Ischiocavernosus
Bulbospongiosus
Superficial
transverse
perineal muscle
Levator ani
Gluteus maximus
(c)
Male
Copyright © 2010 Pearson Education, Inc.
Female
Figure 10.12c
Superficial Muscles of the Thorax
• Most are extrinsic shoulder muscles
• Act in combination to fix the shoulder girdle (mostly
the scapula) and move it to increase range of arm
movements
• Actions include: elevation, depression, rotation,
lateral and medial movements, protraction, and
retraction
• Two groups of muscles: anterior and posterior
A&P Flix™: Muscles that act on the shoulder joint
and humerus: An overview (a)
PLAY
A&P Flix™: Muscles that act on the shoulder joint
and humerus: An overview (b)
Copyright © 2010 Pearson Education, Inc.
PLAY
Superficial Muscles of the Thorax
• Anterior extrinsic shoulder muscles
1. Pectoralis minor
2. Serratus anterior
3. Subclavius
• (Pectoralis major considered later with muscles that
act on the humerus)
PLAY
A&P Flix™: Muscles of the pectoral girdle (a)
PLAY
A&P Flix™: Muscles of the pectoral girdle (b)
Copyright © 2010 Pearson Education, Inc.
Sternocleidomastoid
Subclavius
Clavicle
Subscapularis
Pectoralis minor
Deltoid
Pectoralis
major
Sternum
Coracobrachialis
Serratus anterior
Biceps brachii
Humerus
(a)
PLAY
A&P Flix™: Muscles that act on the shoulder joint
and humerus: An overview (b)
Copyright © 2010 Pearson Education, Inc.
Figure 10.13a
Superficial Muscles of the Thorax
PLAY
A&P Flix™: Pectoralis minor
PLAY
A&P Flix™: Serratus anterior
Copyright © 2010 Pearson Education, Inc.
Superficial Muscles of the Posterior Thorax
• Posterior extrinsic shoulder muscles
1. Trapezius
2. Levator scapulae
3. Rhomboids (major and minor)
• (Latissimus dorsi considered later with muscles that
act on the humerus)
PLAY
A&P Flix™: Muscles of the pectoral girdle (c)
PLAY
A&P Flix™: Movement of the pectoral girdle
Copyright © 2010 Pearson Education, Inc.
Levator
scapulae
Trapezius
Supraspinatus
Clavicle
Deltoid
Rhomboid
minor
Rhomboid
major
Spine of
scapula
Infraspinatus
Teres minor
Teres major
Humerus
Latissimus
dorsi
(c)
Copyright © 2010 Pearson Education, Inc.
Figure 10.13c
Superficial Muscles of the Posterior Thorax
PLAY
A&P Flix™: Trapezius
PLAY
A&P Flix™: Levator scapula
PLAY
A&P Flix™: Rhomboid major
PLAY
A&P Flix™: Rhomboid minor
Copyright © 2010 Pearson Education, Inc.
Muscles Crossing the Shoulder Joint
• Nine muscles cross the shoulder joint to insert on
and move the humerus
• Some originate off the scapula; others originate off
the axial skeleton
• Three are prime movers of the arm
1. Pectoralis major
2. Latissimus dorsi
3. Deltoid
• Actions include flexion, extension, adduction,
abduction, and rotation of humerus
Copyright © 2010 Pearson Education, Inc.
Clavicle
Deltoid
Sternum
Pectoralis major
Coracobrachialis
Triceps brachii:
Lateral head
Long head
Medial head
Biceps brachii
Brachialis
Brachioradialis
(a) Anterior view
Copyright © 2010 Pearson Education, Inc.
Figure 10.14a
Supraspinatus*
Spine of scapula
Deltoid (cut)
Greater tubercle
of humerus
Infraspinatus*
Teres minor*
Teres major
Triceps brachii:
Lateral head
Long head
Latissimus dorsi
Humerus
Olecranon process
of ulna
Anconeus
(b) Posterior view
Copyright © 2010 Pearson Education, Inc.
* Rotator cuff muscles
Figure 10.14b
Muscles Crossing the Shoulder Joint
PLAY
A&P Flix™: Pectoralis major
PLAY
A&P Flix™: Latissimus dorsi
PLAY
A&P Flix™: Deltoid
Copyright © 2010 Pearson Education, Inc.
Muscles Crossing the Shoulder Joint
• Four muscles are rotator cuff muscles:
1. Supraspinatus
2. Infraspinatus
3. Teres minor
4. Subscapularis
• Reinforce the capsule of the shoulder
• Act as synergists and fixators
• Two additional muscles are synergists:
coracobrachialis and teres major
Copyright © 2010 Pearson Education, Inc.
Muscles Crossing the Shoulder Joint
PLAY
A&P Flix™: Muscles that cross the glenohumeral joint
PLAY
A&P Flix™: Movement from the rotator cuff muscles (a)
PLAY
A&P Flix™: Movement from the rotator cuff muscles (b)
PLAY
A&P Flix™: Teres Major
Copyright © 2010 Pearson Education, Inc.
Rotator Cuff Anatomy and Function
PLAY
A&P Flix™: Subscapularis
PLAY
A&P Flix™: Supraspinatus
PLAY
A&P Flix™: Infraspinatus
PLAY
A&P Flix™: Teres minor
PLAY
A&P Flix™: Rotator cuff muscles
Copyright © 2010 Pearson Education, Inc.
Supraspinatus*
Spine of scapula
Deltoid (cut)
Greater tubercle
of humerus
Infraspinatus*
Teres minor*
Teres major
Triceps brachii:
Lateral head
Long head
Latissimus dorsi
Humerus
Olecranon process
of ulna
Anconeus
(b) Posterior view
Copyright © 2010 Pearson Education, Inc.
* Rotator cuff muscles
Figure 10.14b
Clavicle
Deltoid
Sternum
Pectoralis major
Coracobrachialis
Triceps brachii:
Lateral head
Long head
Medial head
Biceps brachii
Brachialis
Brachioradialis
(a) Anterior view
Copyright © 2010 Pearson Education, Inc.
Figure 10.14a
Rotator Cuff Anatomy and Function
PLAY
A&P Flix™: Scapular muscles of the glenohumeral joint (a)
PLAY
A&P Flix™: Axial muscles of the glenohumeral joint (a)
Copyright © 2010 Pearson Education, Inc.
Rotator Cuff Anatomy and Function
PLAY
A&P Flix™: Scapular muscles of the glenohumeral joint (b)
PLAY
A&P Flix™: Axial muscles of the glenohumeral joint (b)
Copyright © 2010 Pearson Education, Inc.
Copyright © 2010 Pearson Education, Inc.
Table 10.12 Part 1
Movement at the Glenohumeral Joint
PLAY
A&P Flix™: Movement at the glenohumeral joint: An overview
PLAY
A&P Flix™: Movement at the glenohumeral joint (a)
PLAY
A&P Flix™: Movement at the glenohumeral joint (b)
Copyright © 2010 Pearson Education, Inc.
Muscles Crossing the Elbow Joint
• Anterior flexor muscles
1. Brachialis and biceps brachii — chief forearm
flexors
2. Brachioradialis — synergist and stabilizer
PLAY
A&P Flix™: The elbow joint and forearm: An overview
PLAY
A&P Flix™: Muscles of the elbow joint (a)
Copyright © 2010 Pearson Education, Inc.
Clavicle
Deltoid
Sternum
Pectoralis major
Coracobrachialis
Triceps brachii:
Lateral head
Long head
Medial head
Biceps brachii
Brachialis
Brachioradialis
(a) Anterior view
Copyright © 2010 Pearson Education, Inc.
Figure 10.14a
Muscles Crossing the Elbow Joint
PLAY
A&P Flix™: Muscles of the elbow joint (b)
PLAY
A&P Flix™: Biceps brachii
PLAY
A&P Flix™: Brachialis
PLAY
A&P Flix™: Brachioradialis
Copyright © 2010 Pearson Education, Inc.
Muscles Crossing the Elbow Joint
• Posterior extensor muscles
1. Triceps brachii — prime mover of forearm
extension
2. Anconeus — weak synergist
Copyright © 2010 Pearson Education, Inc.
Supraspinatus*
Spine of scapula
Deltoid (cut)
Greater tubercle
of humerus
Infraspinatus*
Teres minor*
Teres major
Triceps brachii:
Lateral head
Long head
Latissimus dorsi
Humerus
Olecranon process
of ulna
Anconeus
(b) Posterior view
Copyright © 2010 Pearson Education, Inc.
* Rotator cuff muscles
Figure 10.14b
Muscles Crossing the Elbow Joint
PLAY
A&P Flix™: Muscles of the elbow joint (c)
PLAY
A&P Flix™: Triceps brachii
Copyright © 2010 Pearson Education, Inc.
Triceps
brachii
Lateral
head
Long
head
Medial
head
Humerus
Extensors
Flexors
Brachialis
Others
Posterior
compartment
of arm (extends
elbow); innervation:
radial nerve
Short head
Biceps brachii
Long head
(a)
(a) Muscles of the arm
Anterior compartment
of arm (flexes elbow);
innervation:
musculocutaneous
nerve
PLAY
A&P Flix™: Movement at the elbow joint
Copyright © 2010 Pearson Education, Inc.
Figure 10.17a
Copyright © 2010 Pearson Education, Inc.
Table 10.12 Part 2
Muscles of the Forearm
• Actions: movements of the wrist, hand, and fingers
• Most anterior muscles are flexors and insert via the
flexor retinaculum
• Most posterior muscles are extensors and insert
via the extensor retinaculum
• Some forearm muscles act to produce pronation
and supination of the forearm
PLAY
PLAY
A&P Flix™: Muscles that act on the wrist
and fingers: An overview
A&P Flix™: Muscles of the forearm (a)
Copyright © 2010 Pearson Education, Inc.
Muscles of the Forearm
• Pronators:
1. pronator teres
2. pronator quadratus
• Supinator: a synergist with the biceps brachii
PLAY
A&P Flix™: Muscles of the forearm (b)
PLAY
A&P Flix™: Muscles of the forearm (c)
PLAY
A&P Flix™: Pronator teres
PLAY
A&P Flix™: Supinator
Copyright © 2010 Pearson Education, Inc.
Muscles of the Forearm: Anterior Compartment
• Flexors
1. Flexor carpi radialis
2. Palmaris longus
3. Flexor carpi ulnaris
4. Flexor digitorum muscles (superficialis and
profundus)
5. Flexor pollicis longus
PLAY
A&P Flix™: Carpal tunnel
Copyright © 2010 Pearson Education, Inc.
Superficial transverse
ligament of palm
Palmar aponeurosis
Flexor retinaculum
Pronator quadratus
Flexor digitorum
superficialis
Flexor pollicis longus
Flexor carpi ulnaris
Palmaris longus
Flexor carpi radialis
Extensor carpi radialis longus
Brachioradialis
Pronator teres
Medial epicondyle
of humerus
Tendon of biceps brachii
Medial head of
triceps brachii
Biceps brachii
(a)
Copyright © 2010 Pearson Education, Inc.
Figure 10.15a
Muscles of the Forearm: Anterior Compartment
PLAY
A&P Flix™: Anterior Muscles of the wrist and fingers (b)
PLAY
A&P Flix™: Flexor carpi radialis
PLAY
A&P Flix™: Flexor carpi ulnaris
PLAY
A&P Flix™: Flexor digitorum superficialis
Copyright © 2010 Pearson Education, Inc.
Tendon of flexor
digitorum profundus
Tendon of flexor digitorum
superficialis (cut)
Lumbricals
Tendon of flexor
pollicis longus
Thenar muscles of thumb
Tendon of flexor
carpi ulnaris (cut)
Pronator quadratus
Flexor pollicis longus
Flexor digitorum
profundus
Supinator
(c)
Copyright © 2010 Pearson Education, Inc.
Figure 10.15c
Muscles of the Forearm: Anterior Compartment
PLAY
A&P Flix™: Anterior Muscles of the wrist and fingers (a)
Copyright © 2010 Pearson Education, Inc.
Muscles of the Forearm: Posterior Compartment
• Extensors
1. Extensor carpi radialis brevis
2. Extensor carpi radialis longus
3. Extensor digitorum
4. Extensor carpi ulnaris
5. Extensor pollicis brevis
6. Extensor pollicis longus
7. Extensor indicis
8. Abductor pollicis longus
Copyright © 2010 Pearson Education, Inc.
Extensor
expansion
Tendons of
extensor
digitorum
6. Extensor pollicis longus
5. Extensor pollicis brevis
8. Abductor pollicis longus
3. Extensor digitorum
1. Extensor carpi
radialis brevis
2. Extensor carpi radialis
longus
Tendons of extensor carpi
radialis brevis and longus
7. Extensor indicis
Extensor digiti
minimi
4. Extensor carpi ulnaris
Flexor carpi
ulnaris
Anconeus
Insertion of
triceps brachii
Brachioradialis
(a)
Copyright © 2010 Pearson Education, Inc.
Figure 10.16a
Muscles of the Forearm: Posterior Compartment
PLAY
A&P Flix™: Posterior Muscles of the wrist and fingers (b)
PLAY
A&P Flix™: Extensor carpi radialis longus
PLAY
A&P Flix™: Extensor carpi radialis brevis
PLAY
A&P Flix™: Extensor digitorum
PLAY
A&P Flix™: Extensor carpi ulnaris(c)
PLAY
A&P Flix™: Posterior Muscles of the wrist and fingers (a)
Copyright © 2010 Pearson Education, Inc.
Interossei
Extensor indicis
Extensor pollicis brevis
Extensor pollicis longus
Abductor pollicis longus
Supinator
Anconeus
Olecranon process of ulna
(b)
Copyright © 2010 Pearson Education, Inc.
Figure 10.16b
Movements of the Wrist and Fingers
• Flexion and extension
PLAY
A&P Flix™: Movements of the wrist and fingers (a)
• Abduction and adduction
PLAY
A&P Flix™: Movements of the wrist and fingers (b)
Copyright © 2010 Pearson Education, Inc.
Posterior compartment of forearm
(extends wrist and fingers);
innervation: radial nerve
Extensors
Others
Radius
Abductor
pollicis
longus
Pronator
teres
Brachioradialis
(elbow flexor)
Ulna
Flexors
(b) Muscles of the forearm
(b)
Extensors
Flexors
Others
Copyright © 2010 Pearson Education, Inc.
Anterior compartment
of forearm (flexes wrist
and fingers); innervation:
median or ulnar nerve
Figure 10.17b
Copyright © 2010 Pearson Education, Inc.
Figure 10.12 Part 3
Intrinsic Muscles of the Hand
• Small weak muscles
• Lie entirely within the palm of the hand
• Control precise movements of metacarpals and
fingers (e.g., threading a needle)
• Abductors and adductors of the fingers
• Produce opposition — move the thumb toward
the little finger
Copyright © 2010 Pearson Education, Inc.
Finger and Thumb Movements
• Flexion
• Thumb—bends medially along the palm
• Fingers—bend anteriorly
• Extension
• Thumb—points laterally
• Fingers—move posteriorly
Copyright © 2010 Pearson Education, Inc.
Intrinsic Muscles of the Hand
• Three groups:
1. Thenar eminence (ball of the thumb)
2. Hypothenar eminence (ball of the little finger)
• Each of the above groups has a flexor, an abductor, and an
opponens muscle
3. Midpalmar muscles: lumbricals and palmar and dorsal
interossei extend the fingers
• Interossei muscles also abduct and adduct the fingers
Copyright © 2010 Pearson Education, Inc.
Tendons of:
Flexor digitorum
profundus
Flexor digitorum
superficialis
Third
lumbrical
Fourth
lumbrical
Opponens
digiti minimi
Flexor digiti
minimi brevis
Abductor
digiti minimi
Pisiform bone
Flexor carpi
ulnaris tendon
Flexor digitorum
superficialis
tendons
(a) First superficial layer
Copyright © 2010 Pearson Education, Inc.
Fibrous sheath
Second lumbrical
Dorsal interossei
First lumbrical
Adductor pollicis
Flexor pollicis
brevis
Abductor pollicis
brevis
Opponens pollicis
Flexor retinaculum
Abductor pollicis
longus
Tendons of:
Palmaris longus
Flexor carpi radialis
Flexor pollicis longus
Figure 10.18a
Flexor digitorum
profundus tendon
Flexor digitorum
superficialis tendon
Dorsal interossei
Palmar interossei
Adductor pollicis
Opponens digiti
minimi
Flexor pollicis
brevis
Flexor digiti minimi
brevis (cut)
Abductor digiti minimi
(cut)
(b) Second layer
Copyright © 2010 Pearson Education, Inc.
Abductor pollicis
brevis
Opponens pollicis
Flexor pollicis longus
tendon
Figure 10.18b
Palmar interossei
(c) Palmar interossei (isolated)
Copyright © 2010 Pearson Education, Inc.
Figure 10.18c
Dorsal interossei
(d) Dorsal interossei (isolated)
Copyright © 2010 Pearson Education, Inc.
Figure 10.18d
Intrinsic Muscles of the Hand
PLAY
Animation: Rotating hand
Copyright © 2010 Pearson Education, Inc.
Muscles Crossing Hip and Knee Joints
• Most anterior muscles flex the femur at the hip
and extend the leg at the knee (foreswing of
walking)
• Most posterior muscles extend the thigh and
flex the leg (backswing of walking)
• Medial muscles all adduct the thigh
• All three groups are enclosed by the fascia
lata
PLAY
A&P Flix™: Muscles that act on the hip joint and femur:
An overview
Copyright © 2010 Pearson Education, Inc.
Movements of the Thigh
• Include flexion, extension, abduction,
adduction, circumduction, and rotation
• Thigh flexors pass in front of the hip joint
• Iliopsoas (iliacus and psoas major): prime
mover of flexion
• Tensor fasciae latae
• Rectus femoris
• Assisted by medial adductors and sartorius
PLAY
A&P Flix™: Anterior muscles that cross the hip joint
Copyright © 2010 Pearson Education, Inc.
12th rib
Quadratus lumborum
Psoas minor
Iliac crest
Psoas major
Iliopsoas
Iliacus
12th thoracic vertebra
5th lumbar vertebra
Anterior superior iliac spine
Tensor fasciae latae
Pectineus
Sartorius
Quadriceps femoris
• Rectus femoris
• Vastus lateralis
• Vastus medialis
Adductor longus
Gracilis
Adductor magnus
Tendon of quadriceps femoris
Patella
Patellar ligament
(a)
Copyright © 2010 Pearson Education, Inc.
Figure 10.19a
Movements of the Thigh
PLAY
A&P Flix™: Iliopsoas
PLAY
A&P Flix™: Tensor fasciae latae
PLAY
A&P Flix™: Rectus femoris
PLAY
A&P Flix™: Sartorius
Copyright © 2010 Pearson Education, Inc.
Movements of the Thigh
• Thigh extensors
• Hamstring muscles (prime movers of
extension)
• Biceps femoris
• Semitendinosus
• Semimembranosus
• Gluteus maximus (prime mover during
forceful extension)
Copyright © 2010 Pearson Education, Inc.
Gluteus medius
Gluteus maximus
Adductor magnus
Gracilis
Iliotibial tract
Long head Biceps
Short head femoris
Semitendinosus
Semimembranosus
Hamstrings
(a)
Copyright © 2010 Pearson Education, Inc.
Figure 10.20a
Movements of the Thigh
PLAY
A&P Flix™: Biceps femoris
PLAY
A&P Flix™: Semitendinosus
PLAY
A&P Flix™: Semimembranosus
Copyright © 2010 Pearson Education, Inc.
Movements of the Thigh
• Adductors (also medially rotate thigh)
• Adductor magnus
• Adductor longus
• Adductor brevis
• Pectineus
• Gracilis
PLAY
A&P Flix™: Medial muscles that cross the hip joint
Copyright © 2010 Pearson Education, Inc.
Pectineus
(cut)
Adductor
brevis
Adductor
longus
Adductor
magnus
Femur
(b)
PLAY
O = origin
I = insertion
A&P Flix™: Pectineus
Copyright © 2010 Pearson Education, Inc.
Figure 10.19b
Movements of the Thigh
• Abductors
• Gluteus maximus (also laterally rotates thigh)
• Gluteus medius (also medially rotates thigh)
• Gluteus minimus (also medially rotates thigh)
• Piriformis (also laterally rotates thigh)
• Obturator externus (also laterally rotates thigh)
• Obturator internus (also laterally rotates thigh)
• Gemellus (also laterally rotates thigh)
PLAY
A&P Flix™: Posterior muscles that cross the hip joint
Copyright © 2010 Pearson Education, Inc.
Gluteus medius (cut)
Gluteus minimus
Superior
gemellus
Piriformis
Obturator
internus
Obturator
externus
Quadratus
femoris
Inferior
gemellus
Gluteus
maximus
(cut)
(c)
Copyright © 2010 Pearson Education, Inc.
Figure 10.20c
Movements of the Thigh
PLAY
A&P Flix™: Gluteus maximus(c)
PLAY
A&P Flix™: Gluteus medius
Copyright © 2010 Pearson Education, Inc.
Summary of Movement at the Hip Joint
PLAY
A&P Flix™: Movement at the hip joint
Copyright © 2010 Pearson Education, Inc.
Muscles of the Thigh that Move the Knee
Joint
• Quadriceps femoris—sole extensor of the
knee
• Hamstring muscles—flex the knee, and are
antagonists to the quadriceps femoris
PLAY
A&P Flix™: Muscles that cross the knee joint: An overview.
Copyright © 2010 Pearson Education, Inc.
12th rib
Quadratus lumborum
Psoas minor
Iliac crest
Psoas major
Iliopsoas
Iliacus
12th thoracic vertebra
5th lumbar vertebra
Anterior superior iliac spine
Tensor fasciae latae
Pectineus
Sartorius
Quadriceps femoris
• Rectus femoris
• Vastus lateralis
• Vastus medialis
Adductor longus
Gracilis
Adductor magnus
Tendon of quadriceps femoris
Patella
Patellar ligament
(a)
PLAY
A&P Flix™: Movement at the hip joint
Copyright © 2010 Pearson Education, Inc.
Figure 10.19a
Muscles of the Thigh that Move the Knee
Joint
PLAY
A&P Flix™: Anterior extensors that act on the knee
PLAY
A&P Flix™: Rectus femoris
PLAY
A&P Flix™: Vastus lateralis
PLAY
A&P Flix™: Vastus medialis
PLAY
A&P Flix™: Vastus intermedius
Copyright © 2010 Pearson Education, Inc.
Gluteus medius
Gluteus maximus
Adductor magnus
Gracilis
Iliotibial tract
Long head Biceps
Short head femoris
Semitendinosus
Semimembranosus
Hamstrings
(a)
PLAY
A&P Flix™: Movement at the hip joint
Copyright © 2010 Pearson Education, Inc.
Figure 10.20a
Muscles of the Thigh that Move the Knee
Joint
PLAY
A&P Flix™: Posterior flexors that act on the knee
PLAY
A&P Flix™: Biceps femoris
PLAY
A&P Flix™: Semitendinosus
PLAY
A&P Flix™: Semimembranosus
Copyright © 2010 Pearson Education, Inc.
Summary of Movement at the Knee Joint
PLAY
A&P Flix™: Movement at the knee joint
Copyright © 2010 Pearson Education, Inc.
Fascia of the Leg
• A deep fascia of the leg is continuous with the
fascia lata
• This fascia segregates the leg into three
compartments: anterior, lateral, and posterior
• Distally, the fascia thickens and forms the
flexor, extensor, and fibular retinaculae
PLAY
A&P Flix™: Muscles that act on the ankle and foot:
An overview
Copyright © 2010 Pearson Education, Inc.
Muscles of the Leg: Movements
• Various leg muscles produce the following
movements
• Ankle—dorsiflexion and plantar flexion
• Intertarsal joints—inversion and eversion of
the foot
• Toes—flexion and extension
PLAY
A&P Flix™: Movements of the ankle and foot (a)
Copyright © 2010 Pearson Education, Inc.
Muscles of the Anterior Compartment of
the Leg
• Primary toe extensors and ankle dorsiflexors
• Tibialis anterior
• Extensor digitorum longus
• Extensor hallucis longus
• Fibularis tertius (not always present)
PLAY
A&P Flix™: Anterior muscles that act on the ankle and foot
Copyright © 2010 Pearson Education, Inc.
Fibularis longus
Gastrocnemius
Tibia
Tibialis anterior
Extensor digitorum longus
Soleus
Extensor hallucis longus
Fibularis tertius
Superior and inferior
extensor retinacula
Extensor hallucis brevis
Extensor digitorum brevis
(a)
Copyright © 2010 Pearson Education, Inc.
Figure 10.21a
Muscles of the Anterior Compartment of
the Leg
PLAY
A&P Flix™: Tibialis anterior
PLAY
A&P Flix™: Extensor digitorum longus
PLAY
A&P Flix™: Extensor hallucis longus
Copyright © 2010 Pearson Education, Inc.
Muscles of the Lateral Compartment of
the Leg
• Plantar flexion and eversion of the foot
• Fibularis longus
• Fibularis brevis
PLAY
A&P Flix™: Lateral muscles that act on the ankle and foot
Copyright © 2010 Pearson Education, Inc.
Patella
Head of fibula
Gastrocnemius
Soleus
Fibularis longus
Extensor digitorum longus
Fibularis brevis
Flexor hallucis longus
Fibular retinaculum
Tibialis anterior
Extensor hallucis longus
Fibularis tertius
Superior and inferior extensor
retinacula
Extensor hallucis brevis
Extensor digitorum brevis
Lateral malleolus
(a)
Copyright © 2010 Pearson Education, Inc.
5th metatarsal
Figure 10.22a
Muscles of the Lateral Compartment of
the Leg
PLAY
A&P Flix™: Fibularis longus
Copyright © 2010 Pearson Education, Inc.
Muscles of the Posterior Compartment of
the Leg
• Flexors of the foot and the toes
• Gastrocnemius
• Soleus
• Plantaris
• Popliteus
• Tibialis posterior
• Flexor digitorum longus
• Flexor hallucis longus
Copyright © 2010 Pearson Education, Inc.
Muscles of the Posterior Compartment of
the Leg
PLAY
PLAY
A&P Flix™: Superficial muscles that act on the ankle
and foot
A&P Flix™: Deep posterior muscles that act on the ankle
and foot
Copyright © 2010 Pearson Education, Inc.
Plantaris
Gastrocnemius Medial head
Lateral head
Tendon of
gastrocnemius
Calcaneal tendon
Medial malleolus
Lateral malleolus
Calcaneus
(a) Superficial view of the posterior leg.
Copyright © 2010 Pearson Education, Inc.
Figure 10.23a
Muscles of the Posterior Compartment of
the Leg
PLAY
A&P Flix™: Gastrocnemius
PLAY
A&P Flix™: Soleus
Copyright © 2010 Pearson Education, Inc.
Gastrocnemius
medial head (cut)
Plantaris (cut)
Gastrocnemius
lateral head (cut)
Popliteus
Soleus (cut)
Tibialis posterior
Fibula
Flexor digitorum
longus
Fibularis longus
Tendon of tibialis
posterior
Fibularis brevis
Flexor hallucis longus
Medial malleolus
Calcaneal tendon (cut)
Calcaneus
(c) The triceps surae has been removed to show the
deep muscles of the posterior compartment.
Copyright © 2010 Pearson Education, Inc.
Figure 10.23c
Muscles of the Posterior Compartment of
the Leg
PLAY
A&P Flix™: Tibialis posterior
PLAY
A&P Flix™: Flexor digitorum longus
PLAY
A&P Flix™: Flexor hallucis longus
Copyright © 2010 Pearson Education, Inc.
Major Actions of Muscles Acting on the
Thigh, Leg, and Foot
• View the next five slides for a summary of the
major actions of the muscles acting on the
thigh, leg, and foot
Copyright © 2010 Pearson Education, Inc.
Adductors
Hamstrings
Vastus
lateralis
Femur
Posterior compartment of
thigh (flexes leg and extends
thigh); innervation: tibial
nerve (portion of sciatic nerve)
Vastus
intermedius
(a)
Rectus femoris
Vastus medialis
Posterior
compartment
muscles
Anterior
compartment
muscle
Medial
compartment
muscles of thigh
and lateral
compartment
muscles of leg
Copyright © 2010 Pearson Education, Inc.
Anterior compartment (extends leg);
innervated by femoral nerve
(a) Muscles of the thigh
Medial compartment (adducts
thigh); innervation: obturator
nerve
Figure 10.25a
Posterior
compartment
muscles
Triceps surae
Anterior
compartment
muscle
Fibula
Medial
compartment
muscles of thigh
and lateral
compartment
muscles of leg
Fibularis
muscles
Posterior compartment
of leg (plantar flexes foot,
flexes toes); innervated
by tibial nerve
(b)
Tibialis
anterior
Tibia
Lateral compartment of leg
(plantar flexes and everts foot);
innervation: superficial
fibular nerve
(b) Muscles of the leg
Copyright © 2010 Pearson Education, Inc.
Anterior compartment of leg
(dorsiflexes foot, extends toes);
innervated by deep fibular nerve
Figure 10.25b
Major Actions of Muscles Acting on the
Ankle and Foot
PLAY
PLAY
PLAY
A&P Flix™: Actions of the muscles of the anterior
compartment of the leg
A&P Flix™: Actions of the muscles of the lateral
compartment of the leg
A&P Flix™: Actions of the muscles of the posterior
compartment of the leg
Copyright © 2010 Pearson Education, Inc.
Copyright © 2010 Pearson Education, Inc.
Table 10.17 Part 1
Copyright © 2010 Pearson Education, Inc.
Table 10.17 Part 2
Intrinsic Muscles of the Foot
• Help flex, extend, abduct, and adduct the toes
• Support the arches of the foot along with
some leg tendons
• Extensor digitorum brevis—dorsal foot muscle
that helps extend the toes
Copyright © 2010 Pearson Education, Inc.
Fibularis longus
Gastrocnemius
Tibia
Tibialis anterior
Extensor digitorum longus
Soleus
Extensor hallucis longus
Fibularis tertius
Superior and inferior
extensor retinacula
Extensor hallucis brevis
Extensor digitorum brevis
(a)
Copyright © 2010 Pearson Education, Inc.
Figure 10.21a
Plantar Muscles
• The plantar muscles occur in four layers
1. Superficial layer
• Flexor digitorum brevis
• Abductor hallucis
• Abductor digiti minimi
2. Second layer
• Flexor accessorius
• Lumbricals
Copyright © 2010 Pearson Education, Inc.
Tendon of flexor hallucis longus
Lumbricals
Flexor hallucis brevis
Flexor digiti minimi brevis
Abductor hallucis
Flexor digitorum brevis
Flexor accessorius
Abductor digiti minimi
Calcaneal tuberosity
(a) First layer (plantar aspect)
Copyright © 2010 Pearson Education, Inc.
Figure 10.24a
Lumbricals
Flexor hallucis brevis
Flexor hallucis longus tendon
Flexor digitorum longus (tendon)
Flexor digiti minimi brevis
Abductor digiti minimi
Flexor accessorius
Fibularis longus (tendon)
Flexor digitorum longus (tendon)
Flexor hallucis longus (tendon)
(b) Second layer (plantar aspect)
Copyright © 2010 Pearson Education, Inc.
Figure 10.24b
Plantar Muscles
3. Third layer
• Flexor hallucis brevis
• Adductor hallucis
• Flexor digiti minimi brevis
4. Deepest layer
• Plantar and dorsal interossei
Copyright © 2010 Pearson Education, Inc.
Adductor hallucis (transverse head)
Adductor hallucis (oblique head)
Interosseous muscles
Flexor hallucis brevis
Flexor digiti minimi brevis
Fibularis longus (tendon)
Flexor accessorius
Flexor digitorum longus (tendon)
Flexor hallucis longus (tendon)
(c) Third layer (plantar aspect)
Copyright © 2010 Pearson Education, Inc.
Figure 10.24c
Plantar interossei
(d) Fourth layer (plantar aspect): plantar interossei
PLAY
Animation: Rotating foot
Copyright © 2010 Pearson Education, Inc.
Figure 10.24d