superficial muscles of the back
DESCRIPTION
Superficial muscles of the back . Kaan Yücel M.D., Ph.D. 05.March.2014 Wednesday. MUSCLES OF THE BACK Extrinsic back muscles Superficial group Movements of the upper limb Intermediate group Attached to the ribs May serve as a respiratory function. - PowerPoint PPT PresentationTRANSCRIPT
Superficial musclesof the back
Kaan Yücel M.D., Ph.D 05.March.2014 Wednesday
MUSCLES OF THE BACKExtrinsic back muscles
Superficial group Movements of the upper limb
Intermediate group Attached to the ribs May serve as a respiratory function.
Intrinsic (deep) back muscles Act on the vertebral columnIts movementsMaintain posture
SUPERFICIAL GROUP OF BACK MUSCLESImmediately deep to the skin and superficial fascia.
Connected with the shoulder girdle.
Attach the superior part of the appendicular skeleton (clavicle, scapula, and humerus) to the axial skeleton (skull, ribs, and vertebral column).
SUPERFICIAL GROUP OF BACK MUSCLESProduce and control limb movements.
Trapezius Latissimus dorsiRhomboid major Rhomboid minor Levator scapulae
TRAPEZIUSCovers posterior aspect of neck & superior half of trunk
trapezium (G. irregular four-sided figure)
TRAPEZIUSmuscle's origin: base of triangle situated along vertebral column muscle's insertion: apex pointing toward tip of shoulder
ScapulaVertebral column
Occipital bone
TRAPEZIUSattaches the pectoral girdle
to cranium & vertebral column
assists in suspending the upper limb.
TRAPEZIUSDescending (superior) fibers elevate the scapula (e.g., when squaring the shoulders).
Middle fibers retract the scapula (i.e., pull it posteriorly).
Ascending (inferior) fibers depress the scapula and lower the shoulder.
TRAPEZIUSSuperior fibers of trapezius
from the skull and upper portion of the vertebral column descend to attach to
lateral 1/3 clavicle & acromion of scapula.
TRAPEZIUS
C7 to T12Lateral 1/3
Spine of scapula
TRAPEZIUSSuperior nuchal line
Spinous processes of C7 to T12
Ligamentum nuchae
External occipital protuberance
Lateral 1/3 of clavicle
Acromion
Spine of scapula
TRAPEZIUSSuperior and inferior fibers work together to rotate the lateral aspect of the scapula upward, which needs to occur when raising the upper limb above the head.
TRAPEZIUSThe trapezius also braces the shoulders by pulling the scapulae posteriorly and superiorly, fixing them in position on the thoracic wall with tonic contraction; consequently, weakness of this muscle causes drooping of the shoulders.
TRAPEZIUSMotor innervation of trapezius accessory nerve [XI]descends from the neck onto the deep surface of the muscle. Proprioceptive fibers from trapezius pass in the branches of the cervical plexus and enter the spinal cord at spinal cord levels C3 &C4.
LATTISIUMUS DORSIL. widest of back
Begins in the lower portion of the back Tapers as it ascends to a narrow tendon that attaches to the humerus anteriorly.
LATTISIUMUS DORSIPosterior axillary fold
LATTISIUMUS DORSI• Spinous processes of T7 to
L5• Sacrum• Iliac crest• Ribs 10 to 12
Floor of intertubercular sulcus of humerus
LATTISIUMUS DORSIPasses from the trunk to the humerus. Acts directly on the glenohumeral joint. Acts indirectly on the pectoral girdle.
LATTISIUMUS DORSIExtendAdduct humerus (arm,upper limb)Medially rotate
can also depress the shoulder, preventing its upward movement
Apley scratch test.
LATTISIUMUS DORSIIn combination with pectoralis major
powerful adductor of the humerus
plays a major role in downward rotation of the scapula in association with this movement.
LATTISIUMUS DORSIalso useful in restoring the upper limb from abduction superior to the shoulder; important in climbing.
In conjunction with pectoralis major, raises the trunk to the arm,
performing chin-ups or climbing a tree
LATTISIUMUS DORSI
LATTISIUMUS DORSIInnervation: thoracodorsal nerve
LEVATOR SCAPULAESuperior 1/3 deep to sternocleidomastoidInferior 1/3 deep to trapezius
LEVATOR SCAPULAE
Upper portion medial
border of scapula
superior to root of spine of scapula
LEVATOR SCAPULAE
LEVATOR SCAPULAEacts with the descending part of the trapezius to elevate the scapula, or fix it! resists forces that would depress it, as when carrying
a load.
LEVATOR SCAPULAEWith rhomboids & pectoralis minor, rotates the scapula, depressing the glenoid cavity
rotating the lateral aspect of scapula inferiorly
LEVATOR SCAPULAEActing bilaterally (also with the trapezius), the levators extend the neck.
Acting unilaterally, may contribute to lateral flexion of the neck
toward the side of the active muscle.
RHOMBOID MAJORRHOMBOID MINOR
Deep to trapezius, inferior to levator scapulae Broad parallel bands Pass inferolaterally from vertebrae to medial border of scapulae
RHOMBOID MINORLower portion of ligamentum nuchae Spinous processes of C7 and T1
Medial border of scapula at the spine of scapula
RHOMBOID MAJORSpinous processes of T3 to T5Medial border of scapula between spine & inferior angle
RHOMBOID MAJOR ET MINORRetract (adduct) and elevate scapula
Assist serratus anterior in holding the scapula against the thoracic wall and fixing the scapula during movements of the upper limb.
Innervation: dorsal scapular nerve branch of brachial plexus
C4 & C5
INTERMEDIATE GROUPOF BACK MUSCLES
SERRATUS POSTERIOR SUPERIORSERRATUS POSTERIOR INFERIOR
.Deep to the muscles in the superficial group
Related to the movements of the thoracic cage
Superficial respiratory muscles
More likely proprioceptive rather than motor in function
.
Serratus posterior superior lies deep to the rhomboids
Serratus posterior inferior lies deep to the latissimus dorsi
SERRATUS POSTERIOR SUPERIORSERRATUS POSTERIOR INFERIOR
.attached to the vertebral column and associated structures mediallyEither descend (fibers of serratus posterior superior) or Ascend (fibers of serratus posterior inferior)
to attach to the ribs. These two muscles therefore elevate and depress the ribs
SERRATUS POSTERIOR SUPERIORSERRATUS POSTERIOR INFERIOR
.
Lower portion of ligamentum nuchaeSpinous processes of C7 to T3Supraspinous ligamentsUpper border of ribs 2 to 5 just lateral to their angles
Spinous processes of T11 to L3Supraspinous ligamentsLower border of ribs 9 to 12 just lateral to their angles
SERRATUS POSTERIOR SUPERIOR
SERRATUS POSTERIOR INFERIOR .first four intercostal spinel nerves
last four intercostal spinel nerves