Muscles of Upper Limb

I) Muscles connecting upper limb to axial steleton

1)Muscles of Pectoral Region : include pectoralis major , pectoralis minor & subclavius.

2) Muscles connecting upper limb to thoracic wall: include pectoral muscles & serratus anterior.

3) Muscles connecting upper limb to vertebral column (Muscles of the back).

1) Muscles of Pectoral Region

Origin Insertion Nerve supply Action
1. Pectoralis a) Clavicular head: front of medial ½ • By U shaped bilaminar tendon • Lateral and • Adduction and medial rotation of
major of clavicle. into lateral lip of bicipital medial pectoral arm.
b) Sterno-Costal head: front of groove . (TLP) nerves. • Clavicular head :Flexion of arm .
sternum, upper 6 costal cartilages • The anterior lamina is formed • Sternocostal head :Extend flexed
and external abdominal oblique by clavicular head . arm→. play important role in
aponeurosis . • The poserior lamina is formed swimming , rowing & climbing.
by Sterno-Costal head . • Accessory muscle of respiration.
• The 2 laminae are continuous at
the lower border of the muscle.

2. Pectoralis • Outer surface of 3,4,5 ribs • Upper surface & medial border • Medial Pectoral • Protraction of scapula by pulling it
minor * N.B: 1. It is deep to perctoralis of coracoid process. nerve anterior and inferior.
major • Depresion of shoulder .
• Accessory muscle of respiration.

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 3. Subclavius • Upper surface of 1st. costo- • Groove on the inferior surface • Nerve to • Depress & Prevent excessive
chondral junction . of middle 1/3 of clavicle . subclavius . upward movement of the clavicle .

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 2) Muscles connecting upper limb to thoracic wall
⁕ These muscles include pectoral muscles and serratus anterior

Origin Insertion Nerve supply Action

Serratus • Lateral part of outer surface of • Anterior surface of medial • Long thoracic • Keep the scapula in contact with
Anterior upper 8 ribs border of scapula. nerve ( nerve the chest wall (its paralysis leading
to serratus to winging of scapula)
anterior ) • Protraction of scapula .
• Rotates the glenoid cavity upwards
during abduction of shoulder joint.

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 3) Muscles Connecting Upper Limb to the vertebral Column
⁕ These are part of muscle of back of trunk and include superficial layer ( trapezius & latissimus dorsi ) and deep layer ( levator scapulae , rhomboids
minor & major).
Muscle Origin Insertion Nerve Supply Action
1. Trapezius • Medial 1/3 of superior nuchal line. • Upper fibers : Posterior border • Spinal • Maintain level & elevation of
• External occipital protuberance. of lateral 1/3 of clavicle. accessory shoulder by upper fibres → their
• The 2 • Ligamentum nuchae • Middle fibers : Medial border of nerve. paralysis → shoulder drop .
muscles • Spine of C7. acromion process & the upper • Nerves C3&4 . • Retraction of the scapula by middle
• Spines & supra-spinous ligaments lip of crest of spine of scapula fibers.
form
of all thoracic vertebrae • Lower fibers: Tubercle of crest • Rotation of glenoid cavity upwards
trapezium
of spine of scapula. during abdction of shoulder by
upper & lower fibres.
2. Latissimus • Posterior 1/3 outer lip of iliac crest • Floor of bicipital groove. •Nerve to • Adduction, extension and medial
dorsi • Spines of lower 6 thoracic • Remember TLP ( Muscles latissimus dorsi rotation of shoulder ( play an
vertebrae. inserted in bicipital groove from ( thoraco-dorsal important role in swimming &
• Thoraco-lumbar fascia medial to lateral ) nerve) rowing).
• Lower 4 ribs. • It has triple relation to teres • Pull the trunk upwards as is
• Dorsal surface of inferior angle of major forming posterior fold of climbing.
scapula axilla . • Accessory muscle of respiration .
3. Levator • Transverse processes of upper 4 • Medial border of scapula above • C3&4 nerves. • Elevate the scapula .
scapulae cervical vertebrae . the root of spine of scapula. • Dorsal scapular • Rotate the scapula so that the
nerve (C5) glenoid cavity looks downwards.
4. Rhomboid • Lower part of ligamentum nuchae , • Medial border of scapula • Dorsal scapular • Rotate the scapula so that the
minor spine of C7 & T1 . opposite the root of spine of nerve (C5) glenoid cavity looks downwards.
scapula. which is also • Retration of the scapula .
. Rhomboid • Spines & supra-spinous ligaments • Medial border of scapula from called nerve to
major from T2 to T5 vertebrae . below the root of spine of rhomboids .
scapula to its inferior angle.

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 Vertebra

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N.B: Triangle of auscultation : Between lower part of lateral border of trapezius , medial border of scapula and
upper border of latissimus dorsi and its floor is rhomboid major .Breath sound in this triangle is clearly auscultated .
boi

Muscles of Back

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N.B: Triangle of auscultation : Between lower part of lateral border of trapezius , medial border of scapula and
upper border of latissimus dorsi and its floor is rhomboid major .Breath sound in this triangle is clearly auscultated .
boi

Muscles of Back

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 Levator scapulae
&
Rhomboids

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 Nerve Supply of Muscles of Back

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 II) Muscles of Scapular region
Muscle Origin Insertion Nerve Supply Action
1- Deltoid •
Anterior fibers :Anterior border • Deltoid •Circumflex a) Anterior fibres : flexion & medial
of lateral 1/3 of clavicle . tuberosity ( axillary) nerve rotation of shoulder.
• Middle fibers :Lateral border of of humerus • Injury of axillary nerve b) Posterior fibres: extension & lateral
acromion process. leading to flat shoulder & rotation of shoulder.
• Posterior fibers :Lower border of loss of abduction of c) Middle fibres: Abduction of shoulder (
crest of spine of scapula. shoulder ( 15 -90 degree ) . 15 -90 degree )
⁕ Relations of deltoid :
I) Delto-pectoral groove: related to upper part of cephalic vein , deltopectoral lymph nodes & deltoid branch of thoraco-acromial vessels .
II) Deep relations : It envelop the anterior , lateral and posterior aspect of shoulder joint therefore it is related to the followings :
1) Bones : Upper end of humerus & coracoids process. 2) Coraco-acromial ligament 3) Subacromial bursa & capsule of shoulder joint,
4) Muscles :
• Tendons inserted in upper part of humerus ( subscapularis , supra-spinatus, infra-spinatus , teres minor )
• Muscles attached to coracoids process ( coracobrachialis , short head of biceps and pectoralis minor ).
• 2 heads of biceps ( long & short) & 2 heads of tricepts ( long and lateral).
5) Vessels and nerves around surgical neck of humerus ( circumflex nerve & circumflex humeral vessels)
2- Subscapularis • Medial 2/3 of Subscapular fossa . • Lesser tubercle of • Upper and lower • Adduction and medial rotation of
* N.B. Anterior surface of this muscle humerus subscapular shoulder.
is related to subscapular vesseles , nerves .
nerves & lymph nodes.
3- supraspinatus. • Medial 2/3 of Supraspinous fossa. • Upper facat of • Suprascapular • Initiation of abduction of shoulder
greater tubercle of nerve . ( 0 – 15 degree ).
humerus
4- Infraspinatus. • Medial 2/3 of Infraspinous fossa. • Middle facet of • Adduction & Lateral rotation of
greater tubercle. shoulder.

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5- Teres minor • Upper 2/3 of dorsal surface of • Lowest facet of the • Circumflex • Adduction & lateral rotation of
lateral border of scapula. greater ( axillary) nerve . shoulder.
tubercleosity
⁕ Subscapularis , supraspinatus , Infraspinatus & Teres minor : Tendons of these muscles blends with the capsule of the shoulder
joint , steady the head of the humerus inside the glenoid cavity and called the rotator cuff muscles .

6- Ters major • Dorsal surface of inferior angle and • Medial lip of • Lower • Adduction , extension and medial
and adjoining part of lower 1/3 of bicipital groove subscapular rotation of shoulder ( play an
lateral border of scapula. (TLP) nerve . important role in swimming like
latissmus dorsi ) .

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 Deep relations of deltoid (Post. view)

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 Nerve Supply of Muscles of Scapular Region

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 III) Muscles of front of Arm

Muscle Origin Insertion Nerve supply Action.

1-Bicepe Brachii a. Long head: arises from the • By rounded tendons int •All muscles of front of arm •
Flexion of forearm .
supraglenoid tubercle , runs in postreior part of radial are supplied by musculo- •
Supination of flexed
the shoulder joint (intra- tulerosity . cutaneous nerve exept pronated forearm at
bcapsular extra- synavial) and • By bicipital aponeurosis lateral part of brachialis radioulnar joints.
leave the joint by passing in the into deep fascia of upper which is supplied by radial • Short head:Week flexor
bicipital groove behind part of medial side of nerve i.e brachialis has of shoulder .
transverse humeral ligament. forearm. This aponeurosis double nerve supply . • Long head: Support head
b. Short hesd: arises from tip of separate median cubital • Musculo-cutaneous nerve of humerus from above .
coracoid process with vein from brachial artery. pierces the coracobrachialis
coracobrachialis . then runs between biceps
and brachialis.
2-Caracobrachialis •Tip of Coracoid process (with •Middle of medial border • Flexion & adduction of
short head of biceps) of humerus shoulder.
3- Brachialis • Lower 1/ 2 of anterior surface • Ulnar tuberosity. • Main flexor of elbow.
of shaft of humerus.
IV) Muscles of Back of Arm

Muscle Origin Insertion Nerve supply Action.

Triceps Brachii a. Long head: infra-glenoid tubrcle • Superior surface of • Radial nerve ( long head • Main extensor of elbow.
(extra-capsular) olecranon process of ulna is supplied in axilla while • Articularis cubiti draw
b. Lateral head : Back of shaft of • Articularis cubiti are few lateral & medial heads up the posterior part of
humerus above spiral groove. fiber inserted in the are supplied in spiral the capsule of elbow
c. Medial head: Back of shaft of humerus fibrous capsule of elbow groove). during extension.
below spiral groove. joint .

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 Nerve Supply of Muscles of Front of Arm

(Musculo-cutaneous Nerve)

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 Nerve Supply of the Triceps

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 Quadrangular and Triangular Spaces

 The long head of triceps descends between teres minor and teres major dividing the space related to these two muscles into 3 spaces:
A. Quadrangular space (laterally): Is bounded:
1. Above: By teres minor (seen from behind) and subscapularis (seen from in front).
2. Below: By teres major.
3. Medially: By long head of triceps.
4. Laterally: By surgical neck of humerus.
* It Transmits: Posterior circumflex humeral vesseles and axillary (circumflex) nerve.
B. upper Triangular space (Medially): Is bounded:
1. Above: By teres minor (seen from behind) and subscapularis (seen from in front).
2. Below: By teres major.
3. Laterally: By long head of triceps.
* It transmits: Circumflex scapular artery.
 Both quadrangular and upper triangular spaces lie in the posterior wall of the axilla and connect the axilla with the back of the shoulder region.
C. Lower triangular space is bounded:
1. Above by: Teres major.
2. Medially by: Long head of triceps.
3. Laterally by: Lateral head of triceps.
* It contains radial nerve and profunda brachii vessels.

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 V) Superficial Group of Muscles of Front of Forearm
• All muscles arise from the front of medial epicondyl of humerus (Common flexor origin i.e. C.F.O.)
• All muscles arise by 2 heads except flexor carpi radialis and palmaris longus.
• All muscles are supplied by median nerve except flexor carpi ulnaris which is supplied by ulnar nerve .
• Common action : week flexors of elbow & flexion of wrist (except pronator teres).•The muscles are arranged from lateral to medial as follows:

Muscle Origin Insertion Action.

1- Pronator teres a) Humeral (superficial ) head: from lower part of medial • Rough area in the middle of • Pronation of forearm at
supracondylar ridg & C.F.O. lateral surface of radius radioulnar joints (main action) .
b) Ulnar (deep) head: medial side of coronoid process of (Pronator tuberosity). • Weak Flexor of elbow.
ulna.
⁕ Relations : 1)Median nerve enters the forearm between the 2 heads of pronator teres while ulnar artery pass deep to the 2 heads .
2) Radial artery & superficial radial nerve cross over its insertion 3) It form the medial boundary of cubital fossa .
2- Flexor carpi • C.F.O. • Base of 2 nd & 3 rd • Common action.
radialis metacarpal bones. • Abduction (Radial deviation) of
hand.
3- Palmaris longus • C.F.O , may be abscent. It has a long tendon • Apex of palmar aponeurosis • Common action .
.
4- Flexor a) Humero-ulnar head: C.F.O. & medial side of coronoid • Into sides of the shaft of • Common action .
digitorum process. middle phalanges of medial • Flexion of metacarpo-
superficialis b) Radial head: anterior oblique line of radius i.e. it has 2 4 fingers. phalangeal & proximal
heads arising from 3 bones. interphalangeal joints of
medial 4 fingers.
⁕ Relations: 1) It is deep to Flexor carpi radialis & Palmaris longus
2) The 4 tendons passing through carpal tunnel deep to flexor retinaculum .
3) Median nerve runs deep to the muscle in the forearm then it lies lateral to the tendons in the carpal tunnel.
4) Radial artery and superficial radial nerve pass superficial to the origin of radial head.
5) In the hand: The superficial palmar arch & palmar aponeurosis are superficial to the tendons of the muscle.

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5- Flexor carpi a) Humoral head: C.F.O. • Pisiform bone & base. of 5th metacarpal • Common action .
ulnaris b) Ulnar head : From medial border of bone • Adduction (ulnar deviation) of
olecranon & upper 2/3 of posterior border the hand .
of ulna
⁕ Ulnar nerve and artery is deep to the muscle in the upper 2/3 of forearm then lateral to the tendon of the muscle in the lower 1/3 of forearm .

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 Nerve Supply of Superficial Group of Front of Forearm

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 Nerves and Arteries in Front of Forearm

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 Flexor Digitorum Superficialis Deep Group of
Muscles of Front
Of Forearm .

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 VI) Deep Group of Muscles of Front of Forearm
• Common origin : interosseous membrane and upper 2/3 of corresponding bone ( except pronator quadrates )
• All muscles are supplied by anterior interosseous nerve (branch of median nerve ) except medial 1/2 of Flexor digitorum profundus which is
supplied by Ulnar nerve.
• Common action : Flexion of wrist and all joints of fingers related( except pronator quadrates ) .
Origin Insertion Action.
1- Flexor digitorum • Upper 2/3 of anterior & • By 4 tendons into base of terminal phalanges • Flexion of wrist & all joints of medial 4
profundus medial surface of shaft of of medial 4 fingers. fingers.
ulna & interosseous
membrane.
⁕ Relations :
• Median nerve pass anterior to flexor digitorum profundus and deep to flexor digitorum superficialis .
• Ulnar nerve and artery pass anterior to medial part of flexor digitorum profundus and deep to flexor carpi ulnaris .
• Anterior interosseous nerve and artery pass anterior to interosseus membrane between flexor digitorum profundus and flexor pollicis longus.
• The 4 tendons of flexor digitorum profundus pass in the carpal tunnel deep to the tendons of flexor digitorum superficialis.
• Each tendon of flexor digitorum profundus gives origin to a lumbaricle muscle .
2- Flexor pollices • Upper 2/3 of anterior surface • Its tendon pass deep to flexor retinaculum the • Flexion of wrist & all joints of thumb.
longus. of shaft of radius & curves lateral , medial to muscles of thenar
interosseous membrane . muscles .
• Base of terminal phalanx of thumb.
3- Pronator • Lower 1/4 of front of ulna • Lower 1/4 of front of radius • Pronation at radioulnar joints .
quadratus. • Bind radius to ulna .

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 Tendons of Flexor Digitorum Profundus and Flexor Pollicis Lonus in the Hand

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 VII) Superficial Group of Muscles of Back of Forearm
• Most of these muscles arises from the front of lateral epicondyle of the humerus i.e. common extensor origin (C.E.O) except muscles number 1,2,7.
• All these muscles are supplied by posterior interosseous nerve (a branch of radial nerve ) except muscles number 1,2&7 which are supplied by radial
nerve.
• Common action : Extension of wrist ( except muscles number 1 & 7 )
• Extensor carpi radialis longus & brevis and extensor carpi ulnaris are the main extensor of wrist .
• These muscles are arranged from lateral to medial as follows:
Muscle Origin Insertion Action
1- Brachioradiaslis. •
Upper 2/3 of lateral • Lateral surface of radius above the styloid • Put forearm in midprone position .
supracondylar ridge process . • Flexion of elbow in the midprone position.
• In the arm it overlap radial nerve and in the forearm it overlap superficial radial nerve & radial artery .
2- Extensor carpi radiaslis • Lower 1/3 of lateral • Dorsal surface of base of 2 nd. • Common action +radial deviation
longus supracondylar ridge metacarpal bone (abduction) of wrist.
3- Extensor carpi radialis • C.E.O. • Dorsal surface of base of 3 rd. • As muscle number 2.
brevis. metacarpal bone
4- Extensor digitorum. • C.E.O. • By 4 tendons join extensor expansion • Common action + extension of metacarpo-
which attached to base of middle & distal phalangeal and interphalangeal joints of
phalanges of medial 4 fingers. medial 4 fingers .
5- Extensor digiti minimi. • C.E.O. • Join extensor expension of little finger • Common action + Extensor of metacarpo-
which attached to base of middle & distal phalangeal and and interphalangeal joints
phalanges of little finger . of little finger.
6. Extensor carpi ulnaris. • C.E.O. • Base of 5 th. matacarpal bone • Common action + ulnar deviation
( adduction) of the wrist.
7. Anconeus • It arises Separately • Lateral aspect of back of olecranon • Assists triceps in extension of elbow .
from lateral epicondyle .

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 VIII) Deep Group of Muscles of Back of Forearm
• All these muscles are supplied by posterior interosseous nerve ( branch of radial nerve ) .
• All arises from back of interosseous membrane and back of shaft of radius or back of shaft of ulna ( except supinator ) .
• These muscles are arranged from above downwards as follows :

Muscles Origin Insertion Action.

1- Supinator •Superficial part : from lateral epicondyle • Anterior, lateral & posterior surface • supination of forearm at radio-
and radial collateral ligament of elbow of upper 1/3 of radius above anterior ulnar joints.
joint. and posterior oblique lines of radius
• Deep part : from supinator fossa & and above insertion of pronator teres .
supinator crest of ulna.
⁕ Relations : The posterior interosseous nerve pierce the muscle in the floor of cubital fossa , winds inside the muscle around the radius inside the
muscle & dividing the muscle into superficial and deep parts , then appears in the back of forearm just above the lower border of the muscle .
2- Abductor pollices • Posterior surface of radius , ulna & • Its tendon accompanies the tendon of • Abduction of carpo-metacarpal
longus interosseous membrane. muscle number 3 to insert into base of joint of thumb .
1st . metacarpal bone.
3- Extensor pollices • Posterior surface of radius & interosseous • Base of proximal phalanx of thumb. • Extension of proximal phalanx of
brevis membrane. thumb.
4- Extensor pollices • Posterior surface of ulna & interossous • Base of terminal phalanx of thumb. • Extension of all joints of thumb.
longus membramne.
5- Extensor indicis • Posterior surface of ulna & interosseous • Joint extensor expansion of index • Extension of all joints of index
membrane.. finger. finger.

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 Supinator & Posterior interosseous nerve

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 Muscles of the Hand
I) Lateral Muscles of the Palm
• These muscles include muscles of thenar eminence (Abductor pollices brevis , Flexor pollices brevis & Opponens polices ) and adductor pollices .
• Common origin of thenar muscles are lateral part of flexor retinaculum, scaphoid & trapezium.
• All these muscles are inserted in proximal plalanx of thumb except opponens pollices .
• All are supplied by median nerve except adductor pollices which is supplied by ulnar nerve .

Muscle Origin Insertion Action.

1- Abductor pollices brevis • Common origin • Common insertion • Abduction of carpo-metacarpal joint
(Superficial & lateral) of the thumb.

2- Flexor pollices brevis • Common origin • Common insertion • Flexion of carpo-metacarpal &
(Superficial & medial) metacarpo-phalangeal joint of the
thumb.
3- Opponens pollices • Common origin • 1 st. metacarpal bone. • Opposition of of the thumb against
(deep to No. 1 & 2) other finger at the carpo-metacarpal
joint of the thumb.
4- Adductor pollices. •It has 2 heads: • Common insertion • Adduction of thumb at the carpo-
(Medial to muscles of thenar a)Transverse head: from front of metacarpal joint .
eminence) shaft of 3rd . metacarpal bone.
b)Oblique head: from base of 2nd.
& 3 rd. metacarpal bone.

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 II) Medial Muscles of the palm
• Common origin: Medial part of flexor retiaculum & pisiform bone & hook of hamate.
• All are muscles of little fingers .
• Common insertion : all inserted in the medial side of the base of proximal phalanx of little finger ( except opponens digiti minim ) .
• All muscles are supplied by ulnar nerve .
Muscle Origin Insertion Action
1- Abductor digiti minimi • Common origin • Common insertion • Abdution of little finger .
2- Flexor digiti minimi • Common origin • Common insertion • Flexion of proximal phalanx of little finger.
th
3- Opponens digiti minim • Common origin • Medial surface of the shaft of 5 metacarpal • Opponens little finger against thumb.
bone
4- Palmaris brevis . • Medial border of • Skin of medial side of the palm . • Deepen the hollow of palm of hand .
palmar aponeurosis

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 III) Intermediate Muscles of the Palm
• All muscles are supplied by ulnar nerve except lateral 2 lumbricals are supplied by median nerve .
• Common insertion : Extensor expansion of medial 4 fingers then extend to the back of terminal phalanges of medial 4 fingers .
• Common action: put the hand in writting position (flexion of metacarpo-phalangeal joint & extension of interphalangeal joints of medial 4 fingers )
Origin Insertion Action
1. 4 Lumbricals • Tendons of flexor • Tendons pass backwards along lateral side of • Common action i.e writing position .
digitorum profundus M/P joints to reach the common insertion.
2. 4 Palmar interossei • Each has one head arise • 1st muscle inserted in medial side of base of • Common action i.e writing position.
from palmar surface of proximal phalanx of the thumb. • Adduction of all fingers towards
1,2,4,5 metacarpal bones. • 2nd muscle pass medial while 3rd &4th muscles the center of middle finger .
pass lateral to M/P of corresponding fingers
to reach the common insertion.
3. 4 dorsal interossei • Each muscle has 2 heads • 1st & 2nd muscle pass lateral while 3rd &4th • Common action i.e writing position.
arises from sides of the muscles pass medial to M/P of corresponding • Dorsal interossei :abduction of
related metacarpal bones . fingers to reach the common insertion. middle 3 fingers from the center of
• N.B: The middle finger receive the 2nd &3rd middle finge.
muscle .

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 Action of intermediate muscles of palm

Common Action Action of interossei

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