3 Thoracolumbar FasciaMOB TCDThree layers of fascia enclosing the muscles of the posterior abdominal wallLaterally fascia is fused and is continuous with internal oblique and transversus abdominis
4 Thoracolumbar Fascia Posterior layer MOB TCDCovers the erector spinae is very strong three layersIt is reinforced by the aponeurosis of latissimus dorsiMedially it is attached to lumbar and sacral spinous processesSuperiorly it extends over the back muscles to be continuous with the deep fascia of the neck
5 Thoracolumbar Fascia Partial origin to internal oblique MOB TCDPartial origin to internal obliqueTransversus abdominusLatissimus dorsiTensile strength of 2000 psiMost important non-contractile structure
6 Thoraco-Lumbar Fascia MOB TCDAnterior layerCovering quadratus lumborum muscle, separating it from the psoas majorAttaches in front of lumbar transverse processes and from iliac crest to12th rib
7 Thoraco-Lumbar Fascia MOB TCDMiddle layerBetween erector spinae and quadratus lumborumAttached to tips of transverse processes of lumbar vertebraeExtending in a vertical plane between the iliac crest and the 12th ribPosterior layer attached to spinous process covers sacrospinalis
8 Superficial Muscles Superficial layer Trapezius Latissimus dorsi MOB TCDSuperficial layerTrapeziusLatissimus dorsiLevator scapulaeRhomboid minor and majorConnect upper limb to trunk
9 TrapeziusMOB TCDThe trapezius is a large, flat, triangular muscle, covering the posterior aspect of the neck and superior half of the trunk.It attaches the pectoral girdle to the skull and the vertebral column.It also helps in suspending the shoulder girdle and rotates the scapula.The trapezius is supplied by the spinal part of the accessory, the eleventh cranial nerve.
10 Trapezius Origin Medial third superior nuchal line MOB TCDOriginMedial third superior nuchal lineLigamentum nuchae and spines and inter spinous ligaments of all thoracic vertebraeInsertionUpper third to lateral third of posterior border of clavicleMiddle third to medial border of acromion and the superior lip of the crest of the spine of the scapula
11 TrapeziusMOB TCDLower third fibres insert into the medial end of spine of scapulaNerve supply: spinal accessory nerve (C1 - 5)Proprioceptive fibres from the C3 - 4 cervical plexus.Actions: upper fibres elevate and extension of the neckMiddle fibres retract scapulaUpper and lower fibres rotation of scapula
12 Trapezius The upper fibres elevate the scapula, shrug shoulders. MOB TCDThe upper fibres elevate the scapula, shrug shoulders.The intermediate fibres draw the medial border of the scapula near to the midline and press against the chest wall.The lower fibres pull the scapula downward and depress the tip of the shoulder.The three parts of the trapezius, acting together, draw the scapula medially and rotate the glenoid fossa superiorly in abduction of the shoulder.
13 Trapezius The trapezius muscle is involved in throwing events MOB TCDThe trapezius muscle is involved in throwing eventsIn racquet sports and in overhead movementsMiddle fibres help to stabilise the scapula in rowing and swimmingIt prevents the glenoid fossa being pulled down when lifting heavy objects with your armsIt also helps when you are holding an object overhead
14 Latissimus DorsiMOB TCDThe latissimus dorsi is a large, wide fan-shaped muscle covering the inferior part of the backIt arises from the spines of the lower six thoracic vertebraeThe lumbar fasciaThe posterior third of the outer lip of the iliac crestThe lower three ribs and the inferior angle of the scapula
15 Latissimus Dorsi It spirals around the teres major MOB TCDIt spirals around the teres majorForms medial part of the posterior fold of the axillaIt is inserted by a flat white bilaminated tendon into the floor of the bicipital grooveNerve supply: thoracodorsal nerve C6,7,8
16 Latissimus Dorsi Extends the shoulder MOB TCDExtends the shoulderPowerful adductor of the arm (climbing muscle)Rotates the humerus medially at the shoulder jointThe latissimus dorsi is an accessory muscle of respiration if humerus is fixedIt is supplied by the thoracodorsal nerve C6,7,8It is involved in activities such as paddling a canoe, climbing and swimming
17 Latissimus DorsiMOB TCDIn freestyle swimming, the latissimus dorsi is a prime mover in the down stroke of the arm, mainly an extension movement and some medial rotationIn canoeing, the muscle is a prime mover in the down stroke of the paddle, a movement of extension, adduction and medial rotation
18 Superficial Muscles Deep to trapezius Levator scapulae MOB TCDDeep to trapeziusLevator scapulaeRhomboid minor and majorThey connect upper limb to trunk
19 Levator Scapulae The levator scapulae muscle lies under the trapezius MOB TCDThe levator scapulae muscle lies under the trapeziusIt has its origin from the transverse processes of the upper four cervical vertebrae (C1 to C4)Inserted into the superior part of the medial border of the scapula
20 Levator ScapulaeMOB TCDThe action of the levator scapulae is to raise the medial margin of the scapula and in doing so rotate it so as to produce downward rotation of the glenoid cavityThe nerve supply is C5 via the nerve to the rhomboids from the roots of the brachial plexus
21 Rhomboid Major and Minor MOB TCDThe rhomboid major and minor muscles lie deep to the trapezius and are not always distinct from each otherRhomboid minor arises from C7 and T1 vertebraeThe major is about twice as wide as the minorArises from T2-5Appearing as parallel bands, they both pass inferiolaterally from the vertebrae.
22 Rhomboid Major and Minor MOB TCDThe rhomboid major and minor muscles work togetherRetract the scapula and rotate it to depress the glenoid cavityHelp the serratus anterior muscle to hold the scapula against the thoracic wallFix the scapula during movements of the upper limbThe nerve supply is C5 via the nerve to the rhomboids from the roots of the brachial plexus
23 Intermediate Serratus posterior is an accessory muscle of respiration MOB TCDSerratus posterior is an accessory muscle of respiration
24 Superficial Layer: Splenius Capitis and Cervicis MOB TCDInferior half of ligamentum nuchae and all the spinous processes of T1-T6Insertion: lateral aspect of mastoid processLateral third of superior nuchal line of occipital bone deep to sternocleidomastoidSplenius cervicisPosterior tubercles of transverse processes C1-C4 posterior to levator scapulae
25 Splenius Capitis and Cervicis MOB TCDActing aloneLateral flexionRotation of head and neck to same sideActing togetherExtension of neck and headNerve supply: dorsal rami inferior cervical nerves.
26 Intrinsic Muscles of Back MOB TCDDeep layer of postural muscles attached to vertebral column and the back of headAnatomically in three layers: superficial, intermediate and deepDeep layer of muscles is responsible for movement of vertebral columnRepresents the intrinsic group of back muscles
27 Intermediate Layer: Erector Spinae MOB TCDLies between anterior and posterior layers of thoraco-lumbar fasciaThree vertical columns:medial = spinalisintermediate = longissimuslateral = iliocostalisOrigin: a common broad band from posterior aspect of iliac crestSacrumSacroiliac ligamentsSacral and inferior lumbar spines
28 Erector Spinae: Iliocostalis and Longissimus MOB TCDIliocostalisForms lateral column of erector spinaeInserts into angles of the ribsLongissimusForms the intermediate column of erector spinaeAttached to transverse processes of thoracic and cervical vertebraeMastoid process of temporal bone (muscle has a herring bone appearance)
29 Erector Spinae: Spinalis MOB TCDNarrow medial column of erector spinae (relatively insignificant)Extending to spinous processes of superior lumbar and inferior thoracic region
30 Deep Layer: Transversospinal MOB TCDIn the groove between transverse processes and spines of vertebraeCollectively termed the transversospinal musclesConsists of several short musclesSemispinalisActing bilaterally: extend and stabilise spineActing unilaterally: rotate spine to opposite side and laterally flex
31 Semispinalis Three part muscle Thoracis Cervicis Capitis MOB TCDThree part muscleThoracisCervicisCapitisActing bilaterally it will extend head, neck and thoracic spineActing unilaterally it rotates head and neck to the opposite side
32 Rotatores Short muscle MOB TCDShort muscleAttached from transverse processes of one vertebraTo the base of the spinous process of the vertebra superiorlyAction: rotates the spine to opposite sideMainly in thoracic region