Spine, Chest, Pelvis & Abdomen

Muscle Attachments


Muscle Images

RegionMuscleOriginInsertionAction
AbdomenExternal obliqueLower 8 ribsCrista iliaca, ligamentum inguinaleRotates torso
AbdomenInternal obliqueInguinal ligament, Iliac crest and the Lumbodorsal fasciaLinea alba, Xiphoid process and the inferior ribs.Compresses abdomen and rotates vertebral column.
AbdomenTransversus abdominisRibs and the iliac crestInserts into the pubic tubercle via the conjoint tendon, also known as the falx inguinalisCompress the ribs and viscera, providing thoracic and pelvic stability
AbdomenRectus abdominisPubisCostal cartilages of ribs 5-7, xiphoid process of sternumFlexion of trunk/lumbar vertebrae
AbdomenPyramidalisPubic symphysis and pubic crestLinea albaTensing the linea alba
AbdomenCremasterInguinal ligamentRaise and lower the scrotum
AbdomenQuadratus lumborumIliac crest and iliolumbar ligamentLast rib and transverse processes of lumbar vertebraeAlone, lateral flexion of vertebral column; Together, depression of thoracic rib cage
PelvisIliococcygeusIschial spine and from the posterior part of the tendinous arch of the pelvic fasciaCoccyx and anococcygeal rapheSupports the viscera in pelvic cavity
PelvisPubococcygeusBack of the pubis and from the anterior part of the obturator fasciaCoccyx and sacrumControls urine flow and contracts during orgasm
PelvisPuborectalisLower part of the pubic symphysisInhibit defecation
PelvisCoccygeusSacrospinous ligamentClosing in the back part of the outlet of the pelvis
PerineumSphincter Ani ExternusAnusKeep the anal canal and anus closed, aids in the expulsion of the feces
PerineumSphincter Ani InternusAnusKeep the anal canal and anus closed, aids in the expulsion of the feces
PerineumTransversus perinei superficialisAnterior part of ischial tuberosityCentral point of perineumFixation of central tendon of perineum, support of pelvic floor
PerineumBulbospongiosusMedian raphéIn males, empties the urethra; in females, clenches the vagina
PerineumIschiocavernosusMedian raphéAssists the bulbospongiosus muscle
PerineumTransversus perinei profundusInferior rami of the ischiumIts fellow of the opposite sideFixation of central tendon of perineum, support of pelvic floor, expulsion of semen in male and last drops of urine in both sexes
PerineumSphincter urethrae membranaceaeJunction of the inferior rami [disambiguation needed] of the pubis and ischium to the extent of 1.25 to 2 cm., and from the neighboring fasciæIts fellow of the opposite sideConstricts urethra, maintain urinary continence
ChestIntercostales ExternalRib - inferior borderRib - superior borderInhalation
ChestIntercostales InternalRib - inferior borderRib - superior borderHold ribs steady
ChestIntercostales InnermostRib - inferior borderRib - superior borderHold ribs steady
ChestSubcostalesInner surface of one ribInner surface of the second or third rib above, near its angleHold ribs steady
ChestTransversus thoracisCostal cartilages of last 3-4 ribs, body of sternum, xiphoid processRibs/costal cartilages 2-6Depresses ribs
ChestLevatores costarumTransverse processes of C7 to T12 vertebraeSuperior surfaces of the ribs immediately inferior to the preceding vertebraeAssists in elevation of the thoracic rib cage
ChestSerratus posterior inferiorVertebrae T11 - L3The inferior borders of the 9th through 12th ribsDepress the lower ribs, aiding in expiration
ChestSerratus posterior superiorNuchal ligament (or ligamentum nuchae) and the spinous processes of the vertebrae C7 through T3The upper borders of the 2nd through 5th ribsElevate the ribs which aids in inspiration
ChestDiaphragmRespiration
NeckPlatysmaInferior clavicle and fascia of chestMandibleDraws the corners of the mouth inferiorly and widens it (as in expressions of sadness and fright). Also draws the skin of the neck superiorly when teeth are clenched
NeckSternocleidomastoidManubrium sterni, medial portion of the clavicleMastoid process of the temporal bone, superior nuchal lineActing alone, tilts head to its own side and rotates it so the face is turned towards the opposite side.Acting together, flexes the neck, raises the sternum and assists in forced inspiration. ||
NeckDigastricAnterior belly - digastric fossa (mandible); posterior belly - mastoid process of temporal boneIntermediate tendon (hyoid bone)Opens the jaw when the masseter and the temporalis are relaxed.
NeckStylohyoidStyloid process (temporal)Greater cornu of hyoid boneElevate the hyoid during swallowing
NeckMylohyoidMylohyoid line (mandible)Median raphé [disambiguation needed]Raises oral cavity floor, elevates hyoid, depresses mandible
NeckGeniohyoidSymphysis mentiHyoid boneCarry hyoid bone and the tongue upward during deglutition
NeckSternohyoidManubrium of sternumHyoid boneDepress hyoid bone
NeckSternothyroidManubriumThyroid cartilageElevates larynx, may slightly depress hyoid bone
NeckThyrohyoidThyroid cartilageHyoid boneDepress hyoid bone
NeckOmohyoidUpper border of the scapulaHyoid boneDepresses the larynx and hyoid bone. Carries hyoid bone backward and to the side
NeckLongus colliTransverse processes of C-3 - C-6Inferior surface of the occipital boneFlexes the neck and head
NeckLongus capitisAnterior tubercles of the transverse processes of the third, fourth, fifth, and sixth cervical vertebraeBasilar part of the occipital boneFlexion of neck at atlanto-occipital joint
NeckRectus capitis anteriorAtlasOccipital boneFlexion of neck at atlanto-occipital joint
NeckRectus capitis lateralisUpper surface of the transverse process of the atlasUnder surface of the jugular process of the occipital boneSidebend at atlanto-occipital joint
NeckScalenus AnteriorC3-C6First ribElevate 1st rib, rotate the neck to the opposite side
NeckScalenus MediusC2-C6First ribElevate 1st rib, rotate the neck to the opposite side
NeckScalenus PosteriorTransverse processes of C4 - C62nd ribElevate 2nd rib, tilt the neck to the same side
NeckRectus Capitis Posterior MajorSpinous process of the axis (C2)Inferior nucheal line of the occipital boneExtend and rotate the atlanto-occipital joint
NeckRectus Capitis Posterior MinorThe tubercle on the posterior arch of the atlasThe medial part of the inferior nuchal line of the occipital bone and the surface between it and the foramen magnumExtends the head at the neck, but is now considered to be more of a sensory organ than a muscle
NeckObliquus Capitis InferiorSpinous process of the axisLateral mass of atlasRotation of the head and first cervical vertebra
NeckObliquus Capitis SuperiorLateral mass of atlasLateral half of the inferior nuchal lineExtend the head and flex the head to the ipsilateral side
BackSplenius capitisLigamentum nuchae, spinous process of C7-T6Mastoid process of temporal and occipital boneExtend, rotate, and laterally flex the head
BackSplenius cervicisSpinous processes of T3-T6Transverse processes of C1, C2, C3Bilaterally: Extend the head & neck, Unilaterally: Lateral flexion to the same side, Rotation to the same side
BackErector spinaeOn the spines of the last four thoracic vertebræBoth the spines of the most cranial thoracic vertebrae and the cervical vertebraeExtends the vertebral column
BackIliocostalisSacrum/Illiac Crest/Spinous Processes of lower lumbar/thoracic vertebraeRibsLaterally: Flex the head and neck to the same side. Bilaterally: Extend the vertebral column
BackLongissimusTransverse processTransverse processLaterally: Flex the head and neck to the same side. Bilaterally: Extend the vertebral column.
BackSpinalisSpinous processSpinous processLaterally: Flex the head and neck to the same side. Bilaterally: Extend the vertebral column.
BackLatissimus dorsiSpinous processes of thoracic T6-T12, thoracolumbar fascia, iliac crest and inferior 3 or 4 ribsFloor of intertubercular groove of the humerusAdducts and extends the shoulder
BackSemispinalis dorsiTransverse processes of the sixth to the tenth thoracic vertebræSpinous processes of the upper four thoracic and lower two cervical vertebraeLaterally: Flex the head and neck to the same side. Bilaterally: Extend the vertebral column.
BackSemispinalis cervicisTransverse processes of the upper five or six thoracic vertebræCervical spinous processes, from the axis to the fifthLaterally: Flex the head and neck to the same side. Bilaterally: Extend the vertebral column.
BackSemispinalis capitisTransversal process of lower cervical and higher thoracal columnaArea between superior and inferior nuchal lineExtend the head
BackMultifidusSacrum, Erector spinae Aponeurosis, PSIS, and Iliac crestSpinous processStabilizes vertebrae in local movements of vertebral column
BackRotatoresTransverse processSpinous processStabilizes vertebrae in local movements of vertebral column
BackInterspinalesSpinous processSpinous processExtension, flexion and rotation of vertebral column.
BackIntertransversariiTransverse processTransverse process aboveLateral flexion of trunk