Hsha

1. MUSCLE ILLUSTRATION DESCRIPTION ORIGIN INSERTION NERVE SUPPLY
BLOOD
SUPPLY
ACTION
MUSCLES OF THE PECTORAL REGION
A. Anterior Axioappendicular Muscles (Upper Limb to Thoracic wall)
1. Pectoralis Major
-Fan-shaped muscle; Covers
superior part of thorax
-Convergent
-Has clavicular and
sternocostal heads
-Clavicular head: Anterior
surface of medial half of
clavicle
-Sternocostal head: Anterior
surface of sternum, superior
six costal cartilages, and
aponeurosis of external
oblique muscles
Lateral lip of
intertubercular sulcus
of humerus
Lateral and medial
pectoral nerves
-Adducts and medially
rotates humerus
-Draws scapula anteriorly
and inferiorly
-Clavicular head: flexes
humerus
-Sternocostal head: extends
humerus (from a flexed
position)
2. Pectoralis Minor
-Triangular in shape
-In the anterior wall, almost
completely covered by the
pectoralis major
3rd to 5th ribs near their costal
cartilages
Medial border and
superior surface of
coracoid process of
scapula
Medial pectoral
nerve from brachial
plexus (C8, T1)
Stabilizes scapula by
drawing inferiorly and
anteriorly against thoracic
wall
3. Subclavius
-Found inferior to the clavicle
-Provides protection to the
subclavian vessels and to
the superior trunk of the
brachial plexus
-Resist tendency for clavicle
to be dislocated at the
sternoclavicular joint
Junction of 1st rib and its
costal cartilage
Inferior surface of
middle third of clavicle
Nerve to subclavius
(C5, C6)
Anchors and depresses
clavicle

2. 4. Serratus anterior
-Overlies the lateral part of
the thorax and forms the
medial wall of the axilla
-Named due to sawtooth
appearance of fleshy slips or
digitations
-“Boxer’s muscle” as it is one
of the most powerful muscles
of the pectoral girdle, a
strong protractor of the
scapula, and is used when
punching or reaching
anteriorly
-Multipennate
External surface of lateral
parts of 1st – 8th ribs
Anterior surface of
medial border of
scapula
Long thoracic nerve
(C5, C6, C7)
-Protracts scapula and holds
in against thoracic wall
-Rotates scapula
B. Posterior Axioappendicular muscles (Upper limb to vertebral column)
Superficial (Extrinsic shoulder) muscles
1. Trapezius
-Covers the posterior aspect
of the neck and superior half
of the trunk
-Convergent
-Muscles of the 2 sides form
a trapezium
Medial third of superior
nuchal line; External occipital
protuberance; nuchal
ligament; spinous process of
C7 to T12 vertebrae
-Upper fibers: lateral
third of clavicle
-Middle and lower
fibers: acromion and
spine of scapula
-Spinal accessory
nerve (CN XI)
(motor fibers)
-C3, C4 spinal
nerves (Pain and
proprioceptive
fibers)
-Descending/Superior/Upper
– Elevate scapula
-Middle fibers (all parts
together) – Retracts scapula
-Ascending/Inferior/Lower
fibers – depress scapula

3. 2. Latissimus dorsi
-Large, fan-shaped muscle
-Convergent
-Passes from trunk to the
humerus
-Acts directly on the
glenohumeral joint and
indirectly on the pectoral
girdle (Scapulothoracic joint)
Spinous processes of inferior
6 thoracic vertebrae,
thoracolumbar fascia, iliac
crest, and inferior 3 or 4 ribs
Floor of
intertubercular sulcus
of humerus
Thoracodorsal
nerve (C6, C7, C8)*
-Extends, adducts, and
medially rotates humerus
-Rotates body towards arm
Deep (Extrinsic shoulder) muscles
1. Levator
Scapulae
-Strap-like
-Superior third lies deep to
the sternocleidomastoid;
interior third is deep to the
trapezius
Posterior tubercles of
transverse processes of C1-
C4 vertebrae
Medial border of the
scapula superior to
the root of scapular
spine
Dorsal scapular
(C4, C5) and
Cervical (C3, C4)
nerves
-Elevates scapula medially
-Rotates glenoid cavity
inferiorly by rotating scapula
2. Rhomboid Major
-Forms an oblique equilateral
parallelogram with rhomboid
minor
-Thin, flat, two times wider
than rhomboid minor lying
superior
Spinous processes of T2 to
T5 vertebrae
Medial border of
scapula from level of
spine to inferior angle
Dorsal scapular
nerve (C4, C5)
Retracts scapula and rotates
glenoid cavity inferiorly
-Fix scapula to thoracic wall
3. Rhomboid Minor
-Form an oblique equilateral
parallelogram with rhomboid
major
Nuchal ligament; spinous
process of C7 and T1
vertebrae
Smooth triangular
area at medial end of
scapular spine
Dorsal scapular
nerve (C4, C5)
-Retracts scapula and
rotates its glenoid cavity
inferiorly
-Fix scapula to thoracic wall

4. C. Posterior scapulohumeral muscles (Scapula to Humerus)
1. Deltoid
-Thick, coarse-textured
muscle covering the
shoulder and forms its
rounded contour
(Shaped like the greek letter
delta (triangle))
-Multipennate
-Lateral third of clavicle
-Acromion
-Spine of scapula
Deltoid tuberosity of
the humerus*
Axillary nerve (C5,
C6)
-Clavicular part (anterior):
Flexion and medial rotation
of the arm
-Acromial part (middle):
Abduction of the arm
-Spinal part (posterior):
Extension and lateral
rotation of the arm
2. Supraspinatus
Occupies the supraspinous
fossa of the scapula
Supraspinous fossa of the
scapula
Superior facet of
greater tubercule of
humerus
Suprascapular
nerve (C4, C5, C6)
-Initiates and assists deltoid
in arm abduction
-Acts with rotator cuff
muscles
3. Infraspinatus
Occupies the medial three
quarters of the infraspinous
fossa of the scapula (Partly
covered by the deltoid and
trapezius)
Infraspinous fossa of the
scapula
Medial facet of greater
tubercule of the
humerus
Suprascapular
nerve (C5, C6)
-Lateral rotation of arms
(acts with teres minor)
-Main lateral rotator of the
arm
4. Teres Major
Thick rounded muscle
-Latin “teres”, round
-Assists the Latissimus dorsi
in extending the humerus
Posterior surface of the
inferior angle of the scapula
Medial lip of the
inertubular sulcus of
the humerus*
Lower subscapular
nerve (C5, C6)
Adduction and medial
rotation of arm
5. Teres Minor
Narrow, elongate muscle,
hidden by the deltoid
-Assists the infraspinatus in
lateral rotation of arm and
adduction
Middle part of lateral border
of the scapula
-Inferior facet of
greater tubercule of
the humerus
-Glenohumeral joint
capsule
Axillary nerve (C5,
C6)
Lateral rotation of arms (acts
with infraspinatus)

5. Subscapularis
Thick, triangular muscle lying
on the costal surface of the
scapula
-Forms part of the posterior
wall of the axilla
Subscapular fossa (most of
the anterior surface of the
scapula)
Lesser tubercle of
humerus
Upper and lower
subscapular nerves
(C5, C6, C7)
-Main medial rotator of the
arm
-Assists in holding head of
humerus in the glenoid fossa
Rotator cuff
muscles (SITS)
Muscles involved
Supraspinatus
Infraspinatus
Teres minor
Subscapularis
-Grasps and pulls humeral
head to glenoid cavity
-Protects and stabilizes the
joint capsule
Axillary region
1. Axilla
-Pyramidal space inferior to
glenohumeral joint and
superior to axillary fascia
-Contains loose connective
tissues

6. A. Subspacial spaces
1. Quadrangular
space
Borders:
Teres minor (above)
Teres major (below)
Triceps brachii, long head (medial)
Surgical neck of humerus (lateral)
Axillary nerve
Post humeral circumflex artery
2. Triangular space
(Upper)
Borders:
Teres minor (above)
Teres major (below)
Triceps brachii, long head (lateral)
Circumflex scapular artery from subscapular artery
3. Triangular space
(Lower)
Borders:
Teres major (below)
Triceps brachii, long head (medial)
Humerus (lateral)
Radial nerve
Profunda brachial artery
MUSCLES OF THE ARM
A. Anterior arm: flexor muscles
1. Biceps brachii
-A fusiform with 2 heads that
are proximally attached
-“bi” two + “caput” head
-“Three-joint muscle”
-Although located at the
anterior compartment of the
arm, it has no attachment to
the humerus
-Short head: tip of the
coracoid process of the
scapula
-Long head: supraglenoid
tubercle of the scapula
-Radial tuberosity
-Fascia of the forearm
via bicipital aponeurosis
*Bicipital apneurosis
-A triangular
membranous band that
runs from the biceps
tendon across the
cubital fossa and
merges with the
antebrachial fascia
-Protects the structures
in the cubital fossa and
helps to lessen the
pressure of the biceps
tendon
Musculocutaneous
nerve (C5, C6, C7)
BRACHIAL
ARTERY
-Supination of the
forearm (Primary
supinator)
-Flexion of elbow joint
-Weak flexion of shoulder
-also resists dislocation
of shoulder

7. 2. Brachialis
-A flattened fusiform muscle
lying posterior (deep) to the
biceps
-Main flexor of the forearm
and is the only pure flexor of
the forearm
-Always contracts when the
elbow is flexed
Distal half of anterior surface
of the humerus
-Coronoid process
-Ulnar tuberosity
-Musculocutaneous
nerve (C5, C6)
-Radial nerve (C5,
C7): some lateral
parts are innervated
by a branch of the
radial nerve
BRACHIAL
ARTERY
Flexion of the forearm
3. Coracobrachialis
-Elongated muscle in the
superomedial part of the arm
-Landmark for locating other
structures
-Pierced by the
musculocutaneous nerve
Tip of the coracoid process
of the scapula
Middle third of the
medial surface of the
humerus
Musculocutaneous
nerve (C5, C6, C7)
BRACHIAL
ARTERY
-Flexion and adduction of
the arm
-Resists downward
dislocation of the head of
the humerus (Shunt
muscle)
B. Posterior arm: Extensor muscles
1. Triceps Brachii
-A large fusiform muscle in
the posterior arm
-“tri” three + “caput” head
-Main extensor of the
forearm
-Three heads: long, lateral,
and medial
-Long head: Infraglenoid
tubercle of the scapula
-Lateral head: Posterior
surface of the humerus,
superior to radial groove
(proximal half)
Medial head: Posterior
surface of the humerus,
inferior to radial groove (distal
2/3)
Proximal end of
olecranon of ulna and
fascia of forearm
Radial nerve (C5, C7,
C8)
Profunda
brachii artery
Long head
-least active head
-Extension and
adduction of the arm
-Resists dislocation of
the head of the humerus
(Shunt muscle)
Lateral head
-strongest head
-primarily acts as
resistance
Medial head
-Deep
-Extensor of the forearm
-Active at all speeds with
or without resistance
2. Arconeus
-Small, triangular muscle on
the posterolateral aspect of
the elbow
-partially blended with the
triceps
Posterior surface of lateral
epicondyle of the humerus
-Lateral surface of the
olecranon fossa
-Superior part of the
posterior surface of
the ulna
Radial nerve (C7, C8,
T1)
Profunda
brachii artery
-Assists in extension of
the forearm
-Stabilizes the elbow joint
-Abducts the ulna during
pronation of the forearm

8. MUSCLES OF THE FOREARM
Anterior forearm: Flexor/ Pronator muscles
A. Superficial group – Origin: Common flexor tendon, attached to the medial epicondyle of humerus
1. Pronator Teres
-Located most laterally
-Fusiform muscle
Humeral head: medial
epicondyle of the humerus
Ulnar head: coronoid process
of the Ulna
Lateral aspect of shaft
of radius
Median nerve Pronates and flexes the
forearm
2. Flexor Carpi
radialis
-Located on radial side;
flexes the carpals only, not
the fingers/metacarpals
Medial epicondyle of humerus Base of 2nd metacarpal Median nerve Flexion and abduction of
hand at wrist joint
3. Palmaris longus
Medial epicondyle of humerus Distal half of flexor
retinaculum and
palmar aponeurosis
Median nerve Flexes hand at wrist and
tenses palmar
aponeurosis
Flexor Carpi
Ulnaris *
-Located most medially;
simultaneously flexes and
adductsthe hand at the wrist
Humeral head: medial
epicondyle of humerus
Ulnar head: Olecranon and
posterior border of ulna
-Pisiform
-Hook of hamate
-Base of 5th
metacarpal
Ulnar nerve (C7, C8) Flexion and adduction of
hand at wrist joint
B. Intermediate group – Crosses the elbow
*ALL anterior compartment muscles of the forearm are innervated by the MEDIAN NERVE except the flexor carpi ulnaris and the medial part of the flexor digitorum profundus which are innervated by the ulnar nerve
1. Flexor digitorum
superficialis
-Humeroulnar head: medial
epicondyle of humerus and
coronoid process of ulna
-Radial head: Superior half of
anterior radius
-Bodies of middle
phalanges of medial 4
digits
-Flexes middle and
proximal phalanges of
medial 4 digits
-Flexes hand at wrist
joints

9. C. Deep group
1. Flexor digitorum
profundus (FDP)
(Proximal) medial and anterior
surface of proximal ¾ of ulna
and interosseous membrane
(Distal) palmar base of
distal phalanges of
medial 4 digits
Medial part – Ulnar
nerve
Lateral part – Median
nerve
Assists in flexion of wrist
Stabilizes the elbow joint
Flexes distal
interphalangeal joint
2. Flexor pollicis
longus (FPL)
Lies lateral to the FDP
Long flexor of the thumb
(Proximal) anterior surface of
radius and interosseous
membrane
(Distal) palmar base of
distal phalanx of the
thumb
Median nerve
(anterior
interosseous)
Flexion of thumb
3. Pronator
quadratus
Quadrangular muscle and
pronates the forearm
PRIME MOVER for pronation
DEEPEST muscle in the
anterior aspect of the
forearm
(Proximal) distal 4th of anterior
ulna
(Distal) distal 4th of
anterior radius
Median nerve
(anterior
interosseous)
Pronates forearm
ANTEROIR FOREARM SUBFASCIAL SPACE BOUNDARIES
CONTENTS
(lateral to medial)
1. Cubital
fossa
Triangular area on the
anterior aspect of the
forearm at the area of the
elbow
Site of venipuncture due to
large veins
Lateral – brachioradialis
Medial – pronator teres
Floor – brachialis and
supinator
Roof – brachial and
antebrachial fascia
- Radial nerve and
branches
- Biceps brachii tendon
- Brachial artery and
vein
- Median nerve

10. MUSCLE ILLUSTRATION DESCRIPTION ORIGIN INSERTION NERVE SUPPLY BLOOD SUPPLY ACTION
POSTERIOR FOREARM:
EXTENSOR/ SUPINATOR
MUSCLES
In the posterior compartment of the forearm
Held in place by extensor retinaculum (prevents bowstring o ftendon)
Radial nerve
A. SUPERFICIAL LAYER
1. Brachiradialis
Forms lateral border of
cubital fossa
Proximal 2/3 of
supra-condylar
ridge of humerus
Lateral surfave of
distal end of radius
proximal to styloid
process
Weak flexion of
forearm; Maximal
flexion if forearm is in
midprone position
2. Extensor carpi radialis
longus (ECRL)
Fusiform muscle and is
overlapped by the
brachioradialis
Lateral
supracondylar
ridge of the
humerus
Dorsal base of 2nd
metacarpal
ECRL + ECRB = abducts hand at extension
ECRL + ECRB + Flexor carpi radialis = pure
abduction
ECRL + ECRB + Extensor carpi ulnaris =
extends hand
Extends and abducts
hand at wrist
Active during fist
clenching
3. Extensor carpi radialis
brevis (ECRB)
Lateral epicondyle
of humerus
Dorsal base of 3rd
metacarpal
Extension and
abductin of hand
Acts as synergist to
other muscles
4. Extensor diditorum
Principal extensor of the
digits; Occupying the
posterior surface of the
forearm
Lateral epicondyle
of humerus
Extensor expasions of
medial 4 digits
Extension of medial 4
digits (proximal,
middle, distal
phalanges)
Assist in wrist
extension
5. Extensor digiti minimi
(EDM)
Fusiform slip of muscle
Detached from extensor
digitorum
Lateral epicondyle
of humerus
Extensor expansion of
5th digit
Extension of 5th digit
6. Extensor carpi ulnaris
(ECU)
Long fusiform muscle
Located at the medial
border of the forearm
Lateral epicondyle
of humerus
Posterior border
of ulna
Dorsal aspect of base
of 5th metacarpal
Extension and
adduction of hand
Fist clenching
Synergist to ECRB
B. DEEP GROUP
1. Supinator
PRIME MOVER for
slow, unopposed
supination
Form the floor of cubital
fossa
Lateral epicondyle
of humerus
Supinator fossa
Crest of ulna
Lateral, posterior,
anterior surfaces of
proximal 3rd of radius
Supination of
forearm; Rotation of
radius when elbow is
flexed
2. Abductor pollicis longus
(APL)
Long fusiform belly
Distal to the supinator
Closely related to
extensor pollicis brevis
Posterior surface
of ulna, radius
and interosseous
membrane
Base of 1st
metacarpal
Posterior
interosseus nerve
(continuation of
deep branch of
radial nerve)
Abducts thumb with
Abductor pollicis
brevis
Extends thumb with
Extensor pollicis

11. 3. Extensor pollicis brevis
(EPB)
Lies distal to the
aabductor pollicis
longus
Helps expends the first
metacarpal and abducts
the hand
Posterior surface
of radius and
onterosseous
membrane
Dorsal base of
proximal phalanx of
thums
Posterior
interosseus nerve
(continuation of
deep branch of
radial nerve)
Extension of proximal
phalanx and
carpometacarpal joint
of thumb
4. Extensor pollicis longus
(EPL)
Passes under extensor
retinaculum
Medial to the dorsal
tubercle of the radius
Posterior surface
of middle third of
ulna and
interosseous
membrane
Dorsal base of distal
phalanx of thumb
Posterior
interosseus nerve
(continuation of
deep branch of
radial nerve)
Extension of distal
phalanx of thumb
Adducts and extends
the thumb
Rotates the thumb
laterraly
5. Extensor indicis
Medial alongside to
Extensor pollicis longus
Confers independence
of index finger
Posterior surface
of ulna and
interosseous
membrane
Extensor expansion of
2nd digit
Posterior
interosseus nerve
(continuation of
deep branch of
radial nerve)
Extendion of index
finger and assist in
extension of hand
FASCIAL SPACES and
COMPARTMENTS
Triangular skin
depression on the radial
aspect of wrist
WALLS:
Medial – EPL
Lateral – APL + EPB
FLOOR: Scaphoid +
Trapezium
Radial artery

12. HAND
A. DEEP FASCIA
1. Flexor retinaculum
Makes up CARPAL
TUNNEL –
anterior/palmar side of
wrist that connects the
forearm to the middle
compartment of the
deep plane of the palm
Structures that pass through this muscle:
- 4 tendons of Flexor digitorum
superficialis (FDS)
- 4 tendons of Flexor digitorum
pofundus (FDP)
- 1 tendon of Flexor policis longus
(FPL)
- Median nerve
CARPAL TUNNEL SYNDROME
- Condition where there is pain,
tingling and swelling of hand
caused by pressure on the
MEDIAN NERVE
- Usually affects the thumb, index,
middle and ring fingers
- Relieved surgically (open or
endoscope) releasing the Flexor
retinaculum
2. Extensor retinaculum
Keeps extensor
tendons in place
3. Palmar fascia
Palmar aponeurosis
- Strong well-defined pat of the deep fascia of palm
- Covers soft tissues and overlies long flexor tendons
- Located at Thenar and Hypothenar eminences
Dupuytren Contracture
- Disease of palmar fascia
resulting in progressive
shortening, thickening and
fibrosis of the palmar fascia and
aponeurosis
4. Dorsal fascia
Digital fibrous flexor sheath – covers the flexor digitorum

13. FASCIAL COMPARTMENTS and SPACES LOCATION ADDITIONAL DESCRIPTION
1. Hypothenar
compartment
Space between the
attachment of palmar
aponeurosis to the 5th
metacarpal; Middle of
fibrous septum
Contains hypothenar muscles
2. Thenar compartment
Space between the
attachment of palmar
aponeurosis to the 3rd
metacarpal; Side of the
lateral fibrous septum
Contains thenar muscles
3. Central compartment
Space between the
Hypothenar and Thenar
compartment
Contains:
- Flexor tendons and sheaths
- Lumbricals
- Superficial palmar arterial arch
- Digital vessels and nerves
Adductor compartment: deepest muscular plane of the hand containing the Adductor pollicis
4. Palmar spaces
Midpalmar space
- Under Central compartment
- Covers the flexor group of tendons
Thenar space
- Under Thenar compartment
- Covers the thumb synovial flexor
When there is swelling, this is where the fluid accumulates
5. Synovial flexor sheath
Contains:
Ulnar bursa – protects the Flexor digitorum superficialis and Profundus
Radial bursa – protects the Flexor pollicis longus
B. INTRINSIC MUSCLES OF THE HAND DESCRIPTION ORIGIN INSERTION NERVE SUPPLY BLOOD SUPPLY ACTION
THENAR COMPARTMENT
Median nerve
(recurrent branch)
Thumb movement
(opposition)
1. Abductor pollicis
brevis
Flexor
retinaculum and
Tubercles of
Scaphoid and
Trapezium
Lateral side of
proximal phalanx of
the thumb
Abduction of thumb
2. Flexor pollicis brevis
Flexor
retinaculum and
Tubercles of
Scaphoid and
Trapezium
Lateral side of
proximal phalanx of
the thumb
Median nerve –
large superficial
head
Ulnar nerve –
smaller deep head
Flexes thumb
3. Opponens pollicis
Flexor
retinaculum and
Tubercles of
Scaphoid and
Trapezium
Lateral side of 1st
metacarpal
Oppose thumb by
drawing the 1st
metacarpal medially
to the center of palm
and rotates itmedially

14. HYPOTHENAR COMPARTMENT
DESCRIPTION ORIGIN INSERTION NERVE SUPPLY BLOOD SUPPLY ACTION
Ulnar nerve (deep
branch)
Little finger
movement
1. Abductor digiti minimi
Most superficial among
3 hypothenar muscles
Pisiform Medial side of
proximal phalanx of
5th digit
Abduction of 5th digit,
assists in flexion of
its proximal phalanx
2. Flexor digiti minimi
Hook of hamate
and Flexor
retinaculum
Medial side of
proximal phalanx of
5th digit
Flexes proximal
phalanx of 5th digit
3. Opponens digiti minimi
Hook of hamate
and Flexor
retinaculum
Medial border of 5th
metacarpal
Draws 5th metacarpal
anteriorly and rotates
it to face the thumb
4. Palmaris brevis
NOT in the hypothenar compartment but is part of the hypothenar
eminence
Wrinkles the skin that deepen the hollow of the palm, thereby aiding
palmar grip
CENTRAL COMPARTMENT
1. Lumbricalss
Worm-like form 1st and 2nd –
lateral 2 tendons
of Flexor
digitorum
profundus; 3rd
and 4th – lateral
3 tendons of
Flexor digitorum
Lateral sides of
extensor expansions
of 2nd – 5th digits
1st and 2nd median
nerve; 3rd and 4th
ulnar nerve (deep
branch)
Flex
metacarpophalangeal
joints
Extend
interphalangeal joints
of 2nd – 5th digits
2. Interossei
4 Dorsal interosseous muscles (D) - located between metacarpals
3 Palmar interosseous muscles (P) - located at palmar surface of
the metacarpals in the interosseous compartment of the hand
Ulnar nerve (deep
branch)
D – Abduction (D-Ab)
P – Adduction
(P- Ad)
3. Adductor pollicis
Located at Adductor
compartment of the
hand
Tendon usually
contains sesamoid
bone
Oblique head -
bases of 2nd and
3rd metacarpals,
capitate and
adjacent bones
Transverse head
– anterior
surface of 3rd
metacarpal
Medial side of base
of proximal phalanx
of thumb
Adduction of thumb
toward the lateral
border of palm