TRAPEZIUSTRAPEZIUSIt is a large flat It is a large flat

triangular muscletriangular muscle..OriginOrigin: :

11 . .Occipital boneOccipital bone((aa ) )medial third of medial third of

superior nuchal linesuperior nuchal line..((bb ) )external occipitalexternal occipital

protuberanceprotuberance..

TRAPEZIUSTRAPEZIUS22.. LigamentumLigamentum

nuchaenuchae..33.. SpinesSpines of of

vertebraevertebrae: : C7C7..

All thoracicAll thoracic..44.. SupraspinousSupraspinous

ligamentsligaments..

TRAPEZIUSTRAPEZIUSInsertionInsertion: :

11 . .Upper fibers :Upper fibers : Lateral 1/3 of the Lateral 1/3 of the clavicleclavicle..

22 . .Middle fibers :Middle fibers : Acromion and upper Acromion and upper border of the spine of border of the spine of the the scapulascapula..

33..Lower fibersLower fibers: : Medial end of the Medial end of the

spine of the spine of the scapulascapula..

TRAPEZIUSTRAPEZIUSNerve supplyNerve supply: :

11 . .Spinal partSpinal part of of the the acessoryacessory nerve (11nerve (11thth cranial)cranial)..

22..Sensory Sensory (proprioceptive) (proprioceptive) from from C3 & 4C3 & 4..

TRAPEZIUSTRAPEZIUSActionAction: :

11 . .Upper fibersUpper fibers: : Elevate the scapulaElevate the scapula..

22 . .Middle fibersMiddle fibers: : Retract and pull the Retract and pull the

scapula mediallyscapula medially..33..Lower fibersLower fibers: :

Pull the medial border Pull the medial border of the scapula of the scapula downwards so the downwards so the glenoid cavity faces glenoid cavity faces upward and forwardupward and forward..

TRAPEZIUSTRAPEZIUSActionAction: :

The The upperupper and and lowerlower fibers fibers togethertogether: :

11 . .RotateRotate the the scapula (with scapula (with serratus serratus anterior)anterior)..

22 . .Extend the Extend the head and neckhead and neck..

LATISSMUS DORSILATISSMUS DORSIOriginOrigin: :

11..Posterior part of Posterior part of iliac crestiliac crest..

22 . .Spines of the Spines of the lowerlower six thoracic six thoracic vertebraevertebrae..

33 . .Lower three or Lower three or four four ribsribs..

44 . .Inferior angle of Inferior angle of the the scapulascapula..

LATISSMUS DORSILATISSMUS DORSIIt passes around the It passes around the

lower border of lower border of teres majorteres major (they (they have a triple have a triple relation)relation)..

InsertionInsertion: : Floor Floor of the bicipital of the bicipital

groove of the groove of the humerushumerus

LATISSMUS DORSILATISSMUS DORSINerve supplyNerve supply: : ThoracodorsalThoracodorsal

nervenerve..ActionAction: :

11 . .ExtensionExtension.. 22 . .AdductionAdduction..

33 . .Medial Medial rotationrotation..

of the armof the arm..

LEVATOR SCAPULAELEVATOR SCAPULAEOriginOrigin: :

Transverse processes Transverse processes of the of the upper (4) upper (4) cervical vertebraecervical vertebrae..

InsertionInsertion: : Medial border of the Medial border of the

scapula (oppositescapula (opposite supraspinous fossasupraspinous fossa))..

RHOMBOID MINORRHOMBOID MINOROriginOrigin: :

11 . .Lower part of Lower part of ligamentum nuchaeligamentum nuchae..

22 . .Spines of Spines of C7 &T1C7 &T1..InsertionInsertion: :

Medial border of the Medial border of the scapula (opposite scapula (opposite root root of the of the spine)spine)..

RHOMBOID MAJORRHOMBOID MAJOROriginOrigin: :

A. Spines of A. Spines of (T2-5)(T2-5)..B. Supraspinous B. Supraspinous

ligamentsligaments..InsertionInsertion: :

Medial border of the Medial border of the scapula (opposite scapula (opposite infraspinous fossa)infraspinous fossa)..

NERVE SUPPLYNERVE SUPPLYDorsal scapularDorsal scapular

nerve supplies nerve supplies the Rhomboids the Rhomboids and the Levator and the Levator scapulaescapulae..

Levator Levator has has another supply another supply from from C3&4C3&4..

ACTIONACTION11 . .ElevationElevation of the scapula of the scapula

(medial border)(medial border)..22 . .Acting together and Acting together and

with the with the middle fibersmiddle fibers of of trapeziustrapezius, they pull the , they pull the scapula upwards and scapula upwards and medially and brace themedially and brace the shoulder backwardsshoulder backwards (Retraction)(Retraction)