The Muscles Of The Thoracic Limb/Fore Limb

The Muscles Of The Shoulder Girdle

This group consists of those muscles which connect the thoracic limb with the head,neck,and trunk.It consists of two divisions------Dorsal& Ventral.

A.Dorsal Division

This division consists of two layers.

First Layer

Sr.No Name Of Muscle Horse Ox Dog Origin Insertion

1. Trapezius

Flat,Triangular,Divided into two parts byan aponeuroticportion

Thick,Wide& Undivided

Thin,Dividedinto cervical& thoracicportions byaponeurosis

OxMid-dorsal raphe &supraspinousligament

DogMid-dorsal raphe &supraspinousligament

OxScapular Spine

DogScapular Spine

(a)

Trapezius Cervacalis

HorseFunicular part ofnuchal ligament

HorseScapular Spine &

fascia ofshoulder & arm

(b)Trapezius Thoracalis

Arises by anarrow,thinaponeurosis

HorseSupraspinous

ligament

HorseTuber spine of

scapulaSecond Layer

Sr.No Name Of Muscle Horse Ox Dog Origin Insertion

2.. Rhomboideus

This consists oftwo parts

Has onepart

Rhomboideus Cervicalis

This consists ofthree parts

OxNuchal ligament

DogNuchal ligament,4th – 6th thoracicspine

OxDorsal border& adjacentscapula

DogSame to Ox

(a)Rhomboideus

Cervicalis

(a)Rhomboideus

Cervicalis

HorseFunicular part ofnuchal ligament

DogNuchal ligament asfar forward as C2 orC3

HorseMedial surfaceof cartilage ofscapula

DogMedial surface

of cervicalangle ofscapula

(b)Rhomboideus

Thoracalis

Cervical part isnarrow,pointed at

its anteriorextremity

(b)Rhomboideus

Thoracalis

Small

HorseSpinous process of2nd to 7th thoracicvertebra by meansof dorso-scapularligament

Dog4th- 6th or 7th

thoracic spine

HorseMedial surfaceof cartilage ofscapula

DogMedial surfaceof dorsal angleof scapula

(c)Rhomboideus

Capitis

It is a narrow band Nuchal crest

3. Latissimus Dorsi Wide,Rightangled triangular

Broadestmuscle ofthe back

Extensive,Broadest muscle of the

back

HorseLumbo-dorsal fascia

OxThoraco-lumbar

fasciaDog

Thoraco-lumbarfascia

HorseTerestuberosity ofhumerus,incommon withteres major

OxTerestuberosity ofhumerus

DogTerestuberosity ofhumerus

B.Ventral Division

Sr.No Name Of Muscle Horse Ox Dog Origin Insertion

4. Brachiocephalicus

Extends along theside of neck fromhead toarm,Incompletelydivisible into twoportions

Separated into twoparts by clavicle

Separatedinto two parts

by clavicle

Horse(1)Mastoidprocess oftemporal bone& nuchal crest(2) Wing ofatlas &transverseprocess ofC2,C3,C4

OxOccipital

bone, nuchalligament,mastoidprocess

DogClavicle

HorseDeltoid

tuberosity &crest of

humerus,&the fascia ofshoulder &

armOx

Deltoidtuberosity

and fascia oflimbDog

Medianraphe ofneck &occipitalbone. Theventral partattaches tomastoidprocess

(a)Cleido-mastoideus

Attached to mastoidprocess & occipitalbone by a broadtendon

(a)Cleido-occipitalis

Arises on occipitalbone & nuchalligament

(a)Cleido-cervic

alis

Wider &attached tomedian rapheof neck & tooccipital bone

(b)Cleido-transversarius

Attached totransverse processesby four fleshydigitations

(b)Cleido-mastoideus

Smaller & arisesby round tendonon mastoidprocess & rectuscapitis ventralismajor,& by thintendon onmandible

(b)Cleido-mastoi

deus

Narrow &attached tomastoidprocess

Thinner than in Undivided

OxCranialsternum

DogCranialsternum

OxCranial(descending):crest ofhumerusdistal todeltoidtuberosityCaudal(tran

5.Superficial

Pectoral Muscle

This is of two types horse & its twoparts are not so

clearly separable

&Small

sverse): covers elbowjoint to inserton medialfascia offorearm

DogSame to OX

(a)Anterior Superficial

Pectoral Muscle

Short,Thick,Somewhatrounded,Superficiallyit is convex & deeplyit is flattened

HorseCariniformcartilage of

sternum

Horse(1)Deltoidtuberosity &crest ofhumerus(2)Fascia ofarm

(b)Posterior Superficial

Pectoral Muscle

Wide,Thin &Pale,Mixed with agood deal of fibroustissue

Horse(1)Ventraledge ofsternum as farback as 6th

cartilage(2)Fibrousraphecommon to thetwo muscles

Horse(1)Fascia onproximal 3rd

of forearm(2)Curvedline ofhumerus withprecedingmuscle

More thicker &extensive than

superficial

Undivided,Homologue of subclavius

muscle of man

Has noscapular part

OxVentralsternum andadjacentcartilage

DogVentralsternum and

OxAnterior(subclavius):supraspinatusm.Posterior(pectoralisascendens):

6. Deep PectoralMuscle

muscle,consists oftwo parts

adjacentcartilage

lessertubercle ofhumerus

DogSame to Ox

(a)Anterior Deep

Pectoral Muscle

Prismatic (likeprism),entirely fleshy

HorseAnterior half oflateral surfaceof sternum &cartilages of1st four ribs

HorseAponeurosiswhich coverssupraspinatus at itsdorsal end,&scapularspine

(b)Posterior DeepPectoral Muscle

Largest of pectoralgroup,triangular orfan shaped,entirelyfleshy

Horse(1)Abdominaltunic(2)Xiphoidcartilage&ventral aspectof sternum(3)Carttilagesof 4th -9th ribs

Horse(1)Anteriorpart ofmedialtuberosity ofhumerus(2)Anteriorpart of lateraltuberosity ofhumerus(3)Tendonsof origin ofcoraco-brachialis

Large,Fanshaped,Consists of

two parts

Clearly dividedinto cervical &thoracic parts

No cleardivision intocervical &

thoracic parts

DogLast fivecervicalvertebrae &first eight ribs

DogUpper part ofcostalsurface ofscapula

(a)Serratus Cervicis

(a)Serratus Cervicis

HorseTransverseprocesses of

HorseCranialtriangular

7. Serratus Ventralis

Large last four orfive cervicalvertebrae

Ox

C4-5TH rib

area oncostalsurface ofscapula &adjacent partof cartilage

OxTriangulararea onantero-superior part ofcostalsurface ofscapula

(b)Serratus Thoracis

In domesticatedanimals there is noclear division ofmuscle as is found inman & apes

(b)Serratus Thoracis

Relatively thin &covered by verystrongaponeurosis

HorseLateralsurfaces of 1st

eight or nineribs

Ox

4th-9th ribs

HorseCaudaltriangulararea oncostalsurface ofscapula &adjacent partof cartilage

OxMiddle &posteriorparts ofsubscapularis

8.Omo-transversariu

s Present & unites withCleido mastoideus

Present Present

OxWing of atlas

&inconstantly,tr

ansverseprocess of

OxScapularspine &fasciaDog

Wing of atlas

muscle axisDog

Lower part ofscapular spine

The Muscles Of The Shoulder

The muscles of this group arise on the scapula & end on the arm.They may be divided into two groups---- Lateral Group(covering thelateral) & Medial Group(Covering the costal) surface of scapula.

A.Lateral Group

Sr.No Name Of Muscle Horse Ox Dog Origin Insertion

1. Deltoideus Undivided,Origin is partly

fleshy,Widestabout itsmiddle

Clearlydivided intoacromial &scapularparts

Clearlydivided intoscapular &acromial parts

Horse(1)Upper part ofposterior borderscapula(2)Scapular spine

HorseDeltoid tuberosity &

brachial fascia

(a)Pars

Acromialis

(a)Pars

Acromialis

OxAcromion

DogLength of scapular

OxDeltoid tuberosity on

humerusDog

Short,thick &fusiform

spine Fascia of lateral arm

(b)Pars

Scapularis

(b)Pars

Scapularis

Triangular

OxCaudal border ofscapula,Scapular

spineDog

Lower edge ofacromion

OxDeltoid tuberosity on

humerusDog

Same to Ox

2. SupraspinatusThin at itsneck butbecomesthicker

distally,Branched

Same toHorse

Large

HorseSupraspinous

fossa,Spine,Lowerpart of scapular

cartilageOx

Same to HorseDog

Same to Horse

HorseAnterior parts ofproximal tuberositiesof humerus

OxSame to Horse

DogSame to Horse

3. Infraspinatus Terminates at2 tendon

Terminates at1 tendon

Terminates at1

tendon,Bipennate,

Round

HorseInfraspinous fossa

& Scapularcartilage

OxSame to Horse

DogSame to Horse

Horse(1)Lateral tuberosityof humerus(2)Posterioreminence of lateraltuberosity

OxSame to Horse

DogSame to Horse

Horse(1)Rough lines ondistal & posteriorpart of infraspinousfossa

HorseDeltoid tuberosity &a small area justabove it

Ox

4. Teres MinorFlat,Triangular,Much smallerthan foregoing

muscles

Same toHorse

Short &Fusiform

(2)Caudal border ofscapula(3)Tubercle nearthe rim of glenoidcavity

OxSame to Horse

DogTubercle on caudalborder of scapula

Same to HorseDog

Tubercle on upperpart of deltoid ridge

B.Medial Group

Sr.No Name OfMuscle

Horse Ox Dog Origin Insertion

5. SubscapularisDivided,Flat &

Triangular,Base isthin

Divided into3 branches

Undivided,Wide,

Multipennate,

Intersectedby fibrous

septa

HorseSubscapular fossa

OxDeep surface of

scapula

DogSame to Ox

HorsePosterior

eminence ofmedial tuberosity

of humerus

OxMedial tubercle of

humerusDog

Same to Ox

6. Teres Major Flat,Widest at itsmiddle,Most part is

Same toHorse

More Thick

HorseCaudal angle &adjacent caudal

border of scapulaOx

Same to HorseDog

Dorsal part of the

HorseTeres tuberosity

of humerus incommon with

latissimus dorsiOx

Same to HorseDog

fleshy caudal scapula Teres tuberositymidway down

humerus

7. Coraco-brachialis

Belly spreads out &divided into two

parts

Same toHorse

Short &Undivided

belly

HorseCoracoid process

of scapulaOx

Same to HorseDog

Same to Horse

HorseProximal shaft of

humerusOx

Same to HorseDog

Same to Horse

8. CapsularisVery

small,Fleshy,Onehalf inch wide

Absent Absent

HorseJust above the

caudal part of rimof glenoid cavity

HorseCaudal surface of

shaft ofhumerus,a shortdistance below

head

The Muscles Of The Arm

This group consists of 5 muscles which are grouped around the humerus.They arise from the scapula & humerus,& inserted into theforearm.They act on the elbow joint & the fascia of the forearm.

Sr.No Name OfMuscle

Horse Ox Dog Origin Insertion

1. BicepsBrachii

Strong,Fusiform,Inclosed in a

double sheath offascia,Distallydivide in two

parts,Tendon oforigin is molded

Smaller,Lesstendinous,Situated more medially

than Horse

Long,Fusiform,Tendon of originis round,Tendon

of insertion isbifid

HorseTuber scapulae

OxSupraglenoid

tubercle of scapulaDog

Same to Ox

Horse(1)Radialtuberosity(2)Medial ligamentof elbow joint(3)Fascia offorearm & tendonof extensor carpiradialis

OxMedial tuberosityof proximal radius& adjacent ulna

DogSame to Ox

2. Brachialis Entirely fleshy Very littlecurved

HorseCaudoproximalside of humerus

OxProximocaudal

humerusDog

Same to Ox

HorseCraniomedial sideof proximal radius

OxSpirals to insertnext to biceps

DogSpirals to insertjust proximal to

biceps

Horse Horse

3.TenserFasciae

AntibrachiiThin Slender Thin & Narrow

(1)Tendon ofinsertion oflatissimus dorsi(2)Caudal borderof scapula

OxTendon and lateral

surface of thelatissimus dorsi

DogSame to Ox

(1)Deep fascia offorearm(2)Olecranon

Ox(1)Fascia offorearm(2)Olecranon

DogSame to Ox

4. TricepsBrachii

Clearly dividedinto three heads

Divided intothree heads

Divided into fourheads

(a)Long Head

Largest of threeheads,Powerul,Thick,Triangular

(a)Long Head

(a)Long Head

HorseCaudal border of

scapulaOx

Caudal margin ofscapula

DogCaudal margin of

scapula

HorseLateral & caudal

side of theolecranon

OxOlecranon

DogSame to Ox

(b)Lateral Head

Strong,Quadrilateral,Thick belly

(b)Lateral Head

(b)Lateral Head

HorseHumerus

OxShaft of humerus

DogSame to Ox

HorseLateral surface of

olecranonOx

Olecranon

DogSame to Ox

(c)Medial Head

Smallest ofthree,Fleshy

(c)Medial Head

More developedthan Horse &

(c)Medial Head

Very long

HorseMedial side of

humerusOx

Shaft of humerus

HorseMedial and cranialside of olecranon.

OxOlecranon

except at itsinsertion

extends uptoneck of humerus

DogSame to Ox

DogSame to Ox

(d)Accessory Head

DogShaft of humerus

DogOlecranon

5. Anconeus Small,Entirelyfleshy

Present AbsentHorse

Distal 3rd of caudalsurface ofhumerus

HorseLateral surface of

olecranon

The Muscles Of The Forearm & Manus

A.Extensor Division

Sr.No Name OfMuscle

Horse Ox Dog Origin Insertion

1.Extensor

CarpiRadialis

Largest muscle ofextensor

division,Roundedbelly

Like that of Horse Like that ofHorse

Horse(1)Lateralcondyloid crest ofhumerus(2)Coronoid fossa

OxLateral condyloidcrest of humerus

DogLateral condyloidcrest of humerus

HorseMetacarpaltuberosity

Ox2nd or 3rd

metacarpal boneDog

2nd or 3rd

metacarpal bone

2.Common

DigitalExtensor

LessBulky,Compound,

Fusiform bellyAt fetlock joint itdivides into two

branches

Has four bellies

Horse(1)Distalextremity ofhumerus(2)Proximalextremity ofradius(3)Lateral surfaceof shaft of ulna

Ox(1)Lateralepicondyle ofhumerus(2)Ulna

DogLateral

epicondyle ofhumerus

Horse(1)Extensorprocess of 3rd

phalanx(2)Dorsal face ofproximalextremities of 1st

& 2nd phalangesOx

Extensor processof distal phalanx

of each digit

DogExtensor processof the distalphalanx of eachdigit

3.MedialDigital

ExtensorHas twobranches

More superficialpart

OxLateral

epicondyleDog

Lateral condyloidcrest

OxDorsal proximal

phalangesDog

2nd metacarpalbone

4.LateralDigital

Extensor

Pennate,Thin &fusiform belly

Stronger thanHorse

Not rarely fused

Horse(1)Lateraltuberosity ofradius(2)Shaft of ulna(3)Lateralligament of elbowjoint

Ox(2)Lateralligament of elbowjoint(2)Lateraltuberosity ofradius & ulna

DogLateral

epicondyle ofhumerus

HorseAn eminence onfront of proximalextremity of 1st

phalanxOx

2nd & 3rd

phalanges ofmedial digit

DogDorsal proximalphalanges of 3rd

to 5th digit

5.Extensor

CarpiObliquus

Small,Pennate,Flatbelly,

Same to Horse Abducts the 1st

digit

HorseLateral border of

radiusOx

Cranial radiusDog

Cranial radius

HorseHead of 2nd

metacarpalOx

Most medialmetacarpal bone

Dog1st metacarpal

bone

B.Flexor Division

1. Flexor CarpiRadialis

Short tendon oforigin,Flat & fusiform

bellySame to Horse Has bifid tendons

HorseMedial

epicondyle ofhumerus

OxSame to Horse

DogMedial

epicondyle ofhumerus

HorseProximal end of2nd metacarpal

boneOx

Same to HorseDog

2nd & 3rd

metacarpal bone

2. Flexor CarpiUlnaris

Has two headsHumeral Head:Larger,Flat,Curved,Taper at both endsUlnar Head:Smaller,Very thin

Same to Horse

Has two headsHumeral Head:

LargerUlnar Head:

Smaller

HorseMedialepicondyle ofhumerus

OxSame to Horse

DogMedialepicondyle forhumeral headPosteriorborder forulnar head

HorseProximal edgeof accessorycarpal bone

OxSame to Horse

DogAccessory

carpal bone

HorseLateralepicondyle ofhunerus

Ox

HorseAccessorycarpal bone &proximal side oflateral splint

3. UlnarisLateralis

Flat belly intersected bytendinous tissue

Same to Horse Large,Flat,Abductor of paw

Same to HorseDog

Lateralepicondyle ofhunerus

boneOx

Same to HorseDog

Accessorycarpal bone &5th metacarpal

4. SuperficialDigitalFlexor

Multipennate bellyfuses with deep

flexor,Humeral head isfleshy,Radial head is

strong fibrous

Blended at itsorigin with

middle flexor ofcarpus,

Divides into twobellies(superfici

al & deep)

Divides distally into four branches

Horse(1)Medialepicondyle ofhumerus(2)Caudal sideof radius

OxDigital annularligament

DogMedialepicondyle ofhumerus

Horse(1)Eminence onproximalextremity of 2nd

phalanx(2)Distalextremity of 1st

phalanxOx

Palmar surfaceof middlephalanges

DogMiddle

phalanges of alldigits

5. DeepDigitalFlexor

Largest muscle of flexorgroup,

Has three heads. One originates fromhumerus, one onproximal side of radius,one on proximal side of

Same heads asin Horse

Divides into twobranches neardistal end ofmetacarpus

Same heads as inHorse

Passes throughcarpal canal beforebranching & Then Gives off a branchto 1st digit & divides

Horse(1)Medialepicondyle ofhumerus(2)Medialsurface ofolecranon

OxMedialepicondyle ofhumerus

Dog

HorseSemilunar crest& adjacentsurface ofcartilage of 3rd

phalanxOx

Volar surfacesof 3rd phalanges

Dog3rd phalangesof 2nd to 5th

ulna. into four branches Medialepicondyle ofhumerus

digits

7. LumbricalesTwo very slenderfusiform muscles Absent Very delicate

HorseDeep flexortendon

DogVolar surfaceof tendons ofdeep flexor

HorseFibrous tissueunder nodule ofhorn at fetlock

Dog1st phalanges of3rd,4th,5th digits

8. Interossei

Three innumber,Present inmetacarpal groove

More muscularthan Horse

Divides intothree & theninto fivebranches

Four innumber,Well

developed & fleshy

HorseProximalextremity ofsmallmetacarpalbone

OxDistal row ofcarpus &proximal endsof metacarpals

DogSame to Ox

HorseFascia at fetlock

OxSesamoid bones& detach slips to

the extensortendons

DogSame to Ox

9. PronatorTeres

Absent Present Fusiform

OxMetacarpalbone

DogMedialepicondyle of

Ox2nd & 3rd

phalangesDog

Dorsal surface &medial border of

humerus radius

10.Pronator

Quadratus Absent AbsentConsists of thinlayer of fibers

DogPalmar surface

of radius &interosseous

ligament

DogInterosseousborder of ulna

11. PalmarisLongus Absent Absent Small

DogDeep diditalflexor belowmiddle offorearm

DogSuperficial flexorfor 3rd & 4th

digits

12. Supinator Absent Absent Short,Flat,FusiformDog

Lateralepicondyle of

humerus

DogUpper medialradius

13. PalmarisBrevis

Absent Absent Very small

DogTendon ofsuperficialdidital flexor atcarpus

Dog1ST phalanges of3rd,4th,5th digits

14.AbductorPollicisBrevis

Absent Absent Very small,PaleDog

Fibrous bandconnectingsuperficialflexor tendonwith medialcarpalsesamoid

DogDistal end of 1st

metacarpal bone& 1st phalanx of1st digit

15.FlexorPollicisBrevis

Absent Absent Present

DogVolar carpalligament over2nd metacarpalbone

DogVolar sesamoidof 1st digit

16.AdductorPollicis Absent Present

Largest of thethumb muscles

DogInterossous

Dog1st phalanx of 1st

muscle digit

17.

AdductorDigiti

SecundiAbsent Absent

Present b/w 2nd

interossous muscle& adductor digiti

quinti

DogVolar carpalligament

Dog1st phalanx of2nd digit

18. AdductorDigiti Quinti

Absent Absent PresentDog

Close topreceedingmuscle

Dog1st phalanx of 5th

digit

19. Flexor DigitiQuinti

Absent Absent Present

DogLigamentconnectingaccessorycarpal to 3rd &4th metacarpalbones

Dog5TH digit withnext muscle

20.Abductor

Digiti Quinti Absent AbsentLarger than two

preceedingmuscles

DogAccessorycarpal bone

DogLateralsesamoid of 5th

digit & lateralligaments