THE BACK THE MUSCLES THE MUSCLES OF THE BACK THE MUSCLES OF THE - - PowerPoint PPT Presentation

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THE BACK THE MUSCLES THE MUSCLES OF THE BACK THE MUSCLES OF THE - - PowerPoint PPT Presentation

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THE BACK THE MUSCLES THE MUSCLES OF THE BACK THE MUSCLES OF THE BACK Muscles of the back are organized into superficial , intermediate , and deep groups . extrinsic muscles and intrinsic muscles Muscles in the superficial and intermediate groups

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THE BACK

THE MUSCLES

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THE MUSCLES OF THE BACK

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THE MUSCLES OF THE BACK

Muscles of the back are organized into superficial, intermediate, and deep groups. extrinsic muscles and intrinsic muscles Muscles in the superficial and intermediate groups are extrinsic muscles because they

  • riginate embryologically from locaFons other than the back.
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THE MUSCLES OF THE BACK

The superficial and intermediate groups are innervated by anterior rami of spinal nerves. The superficial group consists of muscles related to and involved in movements of the upper limb. The intermediate group consists of muscles aHached to the ribs and may serve a respiratory funcFon. Muscles of the deep group are intrinsic muscles because they develop in the back.

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THE MUSCLES OF THE BACK

The deep group are are innervated by posterior rami of spinal nerves and are directly related to movements of the vertebral column and head.

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  • SUPERFICIAL EXTRINSIC BACK MUSCLES
  • INTERMEDIATE EXTRINSIC BACK MUSCLES
  • DEEP INTRINSIC BACK MUSCLES

THE BACK MUSCLES

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THE MUSCLES OF THE BACK

The muscles in the SUPERFICIAL GROUP are immediately deep to the skin and superficial fascia.

SUPERFICIAL GROUP OF BACK MUSCLES

They aHach the superior part of the appendicular skeleton:

  • clavicle
  • scapula
  • humerus

to the axial skeleton:

  • skull
  • ribs
  • vertebral column.
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THE MUSCLES OF THE BACK

Because these muscles are primarily involved with movements of this part of the appendicular skeleton, they are someFmes referred to as the appendicular group.

SUPERFICIAL GROUP OF BACK MUSCLES

Muscles in the superficial group include the:

  • trapezius
  • laMssimus dorsi
  • rhomboid major
  • rhomboid minor
  • levator scapulae

The rhomboid major, rhomboid minor, and levator scapulae muscles are located deep to the trapezius muscle in the superior part of the back.

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THE MUSCLES OF THE BACK

THE TRAPEZIUS

SUPERFICIAL GROUP OF BACK MUSCLES

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THE MUSCLES OF THE BACK

Each trapezius muscle is flat and triangular, with the base of the triangle situated along the vertebral column (the muscle's origin) and the apex poinFng toward the Fp of the shoulder (the muscle's inserFon)

THE TRAPEZIUS MUSCLE

The muscles on both sides together form a trapezoid. The superior fibers of the trapezius, from the skull and upper porFon

  • f the vertebral column, descend to aHach to the lateral third of the

clavicle and to the acromion of the scapula. ContracFon of these fibers elevates the scapula.

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THE MUSCLES OF THE BACK

The superior and inferior fibers work together to rotate the lateral aspect of the scapula upward - when raising the upper limb above the head.

THE TRAPEZIUS MUSCLE

ORIGIN: Superior nuchal line, external occipital protuberance, ligamentum nuchae, spinous processes of CVII to TXII INSERTION: Lateral one third of clavicle, acromion, spine of scapula. INNERVATION: Motor: accessory nerve [XI]; propriocepFon: C3 and C4 FUNCTION: Assists in rotaFng the scapula during abducFon

  • f humerus above

horizontal; upper fibers elevate, middle fibers adduct, and lower fibers depress scapula.

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THE MUSCLES OF THE BACK

THE LATISSIMUS DORSI

SUPERFICIAL GROUP OF BACK MUSCLES

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THE MUSCLES OF THE BACK

A large, flat triangular muscle that begins in the lower porMon of the back and tapers as it ascends to a narrow tendon that aHaches to the humerus anteriorly

THE LATISSIMUS DORSI

The movements associated with this muscle include:

  • extension
  • adducFon
  • medial rotaFon of the upper limb.

The laFssimus dorsi can also depress the shoulder, prevenFng its upward movement. The thoracodorsal nerve of the brachial plexus (from posterior cord) innervates the laFssimus dorsi muscle.

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THE MUSCLES OF THE BACK

ORIGIN: Spinous processes of TVII to LV and sacrum, iliac crest, ribs X to XII

THE LATISSIMUS DORSI

INSERTION: Floor of intertubercular sulcus of humerus INNERVATION: Thoracodorsal nerve (C6 to C8). FUNCTION: Extends, adducts, and medially rotates humerus.

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THE MUSCLES OF THE BACK

THE LEVATOR SCAPULAE

SUPERFICIAL GROUP OF BACK MUSCLES

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THE MUSCLES OF THE BACK

A slender muscle that descends from the transverse processes of the upper cervical vertebrae to the upper porFon of the scapula on its medial border at the superior angle

THE LEVATOR SCAPULAE

It elevates the scapula and may assist other muscles in rotaFng the lateral aspect of the scapula inferiorly. The levator scapulae is innervated by branches from the anterior rami

  • f spinal nerves C3 and C4 and the dorsal scapular nerve

ORIGIN: Transverse processes of CI to CIV INSERTION: Upper porFon of medial border of scapula INNERVATION: C3 to C4 and dorsal scapular nerve (C4, C5). FUNCTION: Elevates scapula

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THE MUSCLES OF THE BACK

THE RHOMBOID MINOR

AND

THE RHOMBOID MAJOR

SUPERFICIAL GROUP OF BACK MUSCLES

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THE MUSCLES OF THE BACK

The two rhomboid muscles are inferior to levator scapulae

THE RHOMBOID MUSCLES

Rhomboid minor is superior to rhomboid major. The rhomboid minor arises from the ligamentum nuchae of the neck and the spinous processes of vertebrae CVII and TI and aHaches to the medial scapular border opposite the root of the spine of the scapula. The rhomboid major originates from the spinous processes of the upper thoracic vertebrae TII – TV and aHaches to the medial scapular border inferior to rhomboid minor. The two rhomboid muscles work together to retract

  • r pull the scapula toward the vertebral column.

The dorsal scapular nerve (C4, C5), a branch of the brachial plexus, innervates both rhomboid muscles

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  • SUPERFICIAL EXTRINSIC BACK MUSCLES
  • INTERMEDIATE EXTRINSIC BACK MUSCLES
  • DEEP INTRINSIC BACK MUSCLES

THE BACK MUSCLES

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THE MUSCLES OF THE BACK

The muscles in the intermediate group of back muscles consist of two thin muscular sheets in the superior and inferior regions of the back

INTERMEDIATE GROUP OF BACK MUSCLES

Fibers from these two serratus posterior muscles: serratus posterior superior and serratus posterior inferior pass obliquely outward from the vertebral column to aHach to the ribs. This posiFoning suggests a respiratory funcFon Serratus posterior superior is deep to the rhomboid muscles Serratus posterior inferior is deep to the laFssimus dorsi Both serratus posterior muscles are aHached to the vertebral column.

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THE MUSCLES OF THE BACK

The fibers of the serratus posterior superior DESCEND to aHach to the ribs.

INTERMEDIATE GROUP OF BACK MUSCLES

The fibers of the serratus posterior inferior ASCEND to aHach to the ribs. The serratus posterior muscles are innervated by segmental branches

  • f anterior rami of intercostal nerves.
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  • SUPERFICIAL EXTRINSIC BACK MUSCLES
  • INTERMEDIATE EXTRINSIC BACK MUSCLES
  • DEEP INTRINSIC BACK MUSCLES

THE BACK MUSCLES

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THE MUSCLES OF THE BACK

The deep or intrinsic muscles of the back extend from the pelvis to the skull

DEEP GROUP OF BACK MUSCLES

The deep muscles of the back are innervated by segmental branches

  • f the posterior rami of spinal nerves.

Deep group of back muscles:

  • the extensors and rotators of the head and neck - the splenius

capiFs and cervicis (spinotransversales muscles),

  • the extensors and rotators of the vertebral column - the erector

spinae and transversospinales,

  • the short segmental muscles - the interspinales and

intertransversarii.

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THE MUSCLES OF THE BACK

The deep or intrinsic muscles include the:

  • spinotransversales
  • erector spinae
  • transversospinales
  • segmental
  • suboccipital muscles

DEEP GROUP OF BACK MUSCLES

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THE MUSCLES OF THE BACK

SPINOTRANSVERSALES MUSCLES The two spinotransversales muscles run from the spinous processes and ligamentum nuchae.

DEEP GROUP OF BACK MUSCLES

SPINOTRANSVERSALES MUSCLES:

  • Splenius capiMs is a broad muscle aHached to the occipital bone

and mastoid process of the temporal bone.

  • Splenius cervicis is a narrow muscle aHached to the transverse

processes of the upper cervical vertebrae. SPINOTRANSVERSALES MUSCLES InnervaMon: Posterior rami middle cervical nerves

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THE MUSCLES OF THE BACK

ERECTOR SPINAE The erector spinae is the largest group of intrinsic back muscles.

DEEP GROUP OF BACK MUSCLES

ERECTOR SPINAE The outer or most laterally placed column of the erector spinae muscles is the iliocostalis. ERECTOR SPINAE The outer or most laterally placed column of the erector spinae muscles is the iliocostalis. The middle or intermediate column is the longissimus. The most medial muscle column is the spinalis. ERECTOR SPINAE The muscles lie posterolaterally to the vertebral column between the spinous processes medially and the angles of the ribs laterally.

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THE MUSCLES OF THE BACK

ERECTOR SPINAE The muscles in the erector spinae group are the primary extensors of the vertebral column and head.

DEEP GROUP OF BACK MUSCLES

ERECTOR SPINAE AcFng unilaterally, they bend the vertebral column laterally.

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THE MUSCLES OF THE BACK

TRANSVERSOSPINALES The transversospinales muscles run obliquely upward and medially from transverse processes to spinous processes

DEEP GROUP OF BACK MUSCLES

TRANSVERSOSPINALES Filling the groove between these two vertebral projecFons. TRANSVERSOSPINALES They are deep to the erector spinae TRANSVERSOSPINALES Three major subgroups:

  • semispinalis
  • mulFfidus
  • rotatores muscles
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THE MUSCLES OF THE BACK

TRANSVERSOSPINALES When muscles in the transversospinales group contract bilaterally, they extend the vertebral column

DEEP GROUP OF BACK MUSCLES

acFon similar to that

  • f the erector

spinae group

TRANSVERSOSPINALES One muscle in this group, the semispinalis capiMs, has a unique acFon because it aHaches to the skull. TRANSVERSOSPINALE - the semispinalis capiMs: ContracFng bilaterally, this muscle pulls the head posteriorly TRANSVERSOSPINALE - the semispinalis capiMs: unilateral contracFon pulls the head posteriorly and turns it

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THE MUSCLES OF THE BACK

SEGMENTAL MUSCLES The two groups of segmental muscles:

  • the first group of segmental muscles are the levatores costarum

muscles.

  • the second group of segmental muscles are the true segmental

muscles of the back - the interspinales and the intertransversarii.

DEEP GROUP OF BACK MUSCLES

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THE MUSCLES OF THE BACK

THE THORACOLUMBAR FASCIA

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THE MUSCLES OF THE BACK

The thoracic and lumbar parts of the deep fascia consFtute the thoracolumbar fascia.

DEEP GROUP OF BACK MUSCLES

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THE MUSCLES OF THE BACK

The thoracolumbar fascia is criFcal to the overall organizaFon and integrity of the region:

  • Superiorly, it passes anteriorly to the serratus posterior muscle and

is conFnuous with deep fascia in the neck.

  • In the thoracic region, it covers the deep muscles and separates

them from the muscles in the superficial and intermediate groups.

  • Medially, it aHaches to the spinous processes of the thoracic

vertebrae and, laterally, to the angles of the ribs.

DEEP GROUP OF BACK MUSCLES

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THE MUSCLES OF THE BACK

SUBOCCIPITAL MUSCLES A small group of deep muscles in the upper cervical region at the base

  • f the occipital bone

DEEP GROUP OF BACK MUSCLES

SUBOCCIPITAL MUSCLES include, on each side:

  • rectus capiFs posterior major,
  • rectus capiFs posterior minor,
  • obliquus capiFs inferior,
  • obliquus capiFs superior

INNERVATION: posterior ramus of C1

SUBOCCIPITAL MUSCLES ContracFon of the suboccipital muscles extends the head at the atlantoaxial joint.

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THE MUSCLES OF THE BACK

SUBOCCIPITAL MUSCLES The suboccipital muscles form the boundaries of the suboccipital triangle

DEEP GROUP OF BACK MUSCLES

SUBOCCIPITAL MUSCLES The contents of the suboccipital triangle are

  • the posterior ramus of C1,
  • the vertebral artery,
  • and associated veins.
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THE MUSCLES OF THE BACK

NERVE INJURIES AFFECTING SUPERFICIAL BACK MUSCLES

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THE MUSCLES OF THE BACK

An interrupFon of the accessory nerve [XI] … The accessory nerve [XI] innervates: THE TRAPEZIUS - funcMon: Assists in rotaFng the scapula during abducFon of humerus above horizontal; upper fibers elevate scapula… SYMPTOMS:

  • drooping of the shoulder
  • inability to raise the arm above the head because of impaired

rotaFon of the scapula

  • weakness in aHempFng to raise the shoulder