DEEP MUSCLES OF THE BACK

MUSCLES OF THE BACK - THREE GROUPS

• SUPERFICIAL

• INTERMEDIATE

• DEEP

1. SUPERFICIAL MUSCLES ARE EXTRINSIC

MUSCLES OF THE BACK

SUPERFICIAL MUSCLES - PRODUCE AND

CONTROL LIMB MOVEMENTS

CONNECT PECTORAL GIRDLE TO AXIAL

SKELETON

2. INTERMEDIATE MUSCLES ARE EXTRINSIC

MUSCLES OF THE BACK

INTERMEDIATE MUSCLES - MAY PRODUCE

RESPIRATORY MOVEMENT

3. DEEP MUSCLES OF THE BACK ARE THE

INTRINSIC MUSCLES OF THE BACK

MUSCLES THAT SPECIFICALLY ACT ON

THE VERTEBRAL COLUMN, PRODUCING

ITS MOVEMENTS AND MAINTAINING

POSTURE

SUPERFICIAL (EXTRINSIC) BACK MUSCLES*

1) CONNECT UPPER LIMB TO TRUNK

2) CONTROL LIMB MOVEMENT

*(THESE MUSCLES ARE INNERVATED BY

NERVES FORMED FROM VENTRAL RAMI)

TRAPEZIUS

LATISSIMUS

DORSI

LEVATOR

SCAPULAE

RHOMBOIDS

INTERMEDIATE (EXTRINSIC) BACK MUSCLES*

SERRATUS POSTERIOR SUPERIOR - LIES DEEP TO

THE RHOMBOIDS (RIBS 2 - 5)

SERRATUS POSTERIOR INFERIOR - LIES DEEP TO

THE LATISSIMUS DORSI (RIBS 9 - 12)

MAY BE INVOLVED IN RESPIRATION

*(INNERVATED BY INTERCOSTAL NERVES, THESE

ARE FROM THE VENTRAL RAMI OF THE SPINAL

NERVES)

INTERMEDIATE

LAYER:

SERRATUS

POSTERIOR

SUPERIOR

SERRATUS

POSTERIOR

INFERIOR

DEEP (INTRINSIC) MUSCLES OF THE BACK*

MAINTAIN POSTURE AND CONTROL MOVEMENTS

OF THE VERTEBRAL COLUMN; EXTEND FROM

SKULL TO PELVIS; ASSIST IN MOVEMENT OF

THE HEAD (ALL MUSCLE ARE BILATERAL -

LOCATED ON BOTH SIDES!)

*(INNERVATED BY DORSAL RAMI OF SPINAL

NERVES)

DIVIDED INTO 3 GROUPS:

1. SUPERFICIAL INTRINSIC LAYER

2. INTERMEDIATE INTRINSIC LAYER

3. DEEP INTRINSIC LAYER

1. SUPERFICIAL

INTRINSIC LAYER: SPLENIUS CAPITIS AND

CERVICIS

LARGE FLAT OBLIQUE

BAND DEEP TO

TRAPEZIUS AND

SERRATUS

POSTERIOR SUPERIOR

BOTH EXTEND THE

HEAD AND NECK IF

CONTRACTED

BILATERALLY OR ONE SIDE WILL PULL THE

NECK AND HEAD TO THE

SAME SIDE

2. INTERMEDIATE

INTRINSIC LAYER:

ERECTOR SPINAE

EXTENDS FROM

THE PELVIS TO THE

SKULL

FILLS IN THE SPACE

BETWEEN THE

SPINOUS PROCESSES AND

THE ANGLE OF THE

RIBS

3 DIVISIONS:

ILIOCOSTALIS

LONGISSIMUS

SPINALIS

ILIOCOSTALIS - MOST LATERAL COLUMN

EXTENDS VERTEBRAL COLUMN WHEN

ACTING TOGETHER

BENDS VERTEBRAL COLUMN TO SAME

SIDE IF ONLY ONE SIDE CONTRACTS

(LATERAL FLEXION)

LONGISSIMUS - INTERMEDIATE COLUMN

ACTING TOGETHER EXTENDS

VERTEBRAL COLUMN

ONE SIDE WILL BEND THE VERTEBRAL

COLUMN TO THE SAME SIDE (LATERAL

FLEXION)

SPINALIS - MOST MEDIAL COLUMN

EXTENDS VERTEBRAL COLUMN AND HEAD

REMEMBER - I LOVE SPAGHETTI (LATERAL

TO MEDIAL)

LATERAL -

ILIOCOSTALIS

INTERMEDIATE - LONGISSIMUS

MEDIAL -

SPINALIS

ALL 3 MUSCLES

ARE LOCATED

ON BOTH SIDES

OF THE

VERTEBRAL

COLUMN

3. DEEP INTRINSIC LAYER: TRANSVERSOSPINAL

GROUP

DEEP TO THE SPINALIS

MUSCLE - EXTEND FROM

TRANSVERSE PROCESS TO

SPINOUS PROCESS

3 MUSCLES IN GROUP DEPENDING ON LENGTH OF

FIBERS

ROTATORES SEMISPINALIS - CROSSES

~6 VERTEBRAE

MULTIFIDUS - CROSSES ~4

VERTEBRAE

ROTATORES - CROSS ~1-2

VERTEBRAE

SEMISPINALIS -

CROSSES ~6

VERTEBRAE

MULTIFIDUS - CROSSES ~ 4

VERTEBRAE

(THICKEST IN

LUMBAR REGION BUT ARE LOCATED

THROUGHOUT

THE SPINE)

ROTATORES -

CROSS ~ 1-2

VERTEBRAE

ALL THE TRANSVERSOSPINAL GROUP ROTATE THE

BODY TO THE OPPOSITE SIDE

SEMISPINALIS (6)

MULTIFIDUS (4)

ROTATORES (1-2)

QUADRATUS LUMBORUM

THIS IS NOT A BACK MUSCLE BUT

FORMS PART OF THE POSTERIOR

ABDOMINAL WALL

FILLS IN SPACE FROM THE 12TH

RIB AND THE ILIAC CREST

BOTH SIDES TOGETHER WILL

EXTEND LUMBAR SPINE

ONE SIDE WILL BEND TO THE

SAME SIDE (LATERAL FLEXION)

THREE LAYERS OF MUSCLES IN THE

BACK:

SUPERFICIAL - CONNECT AND MOVE

UPPER LIMB

INTERMEDIATE - AID IN RESPIRATION

DEEP - MOVE THE VERTEBRAL COLUMN,

MAINTAIN POSTURE

DEEP OR INTRINSIC MUSCLES OF THE

BACK DIVIDED INTO THREE GROUPS:

SUPERFICIAL - SPLENIUS CAPITIS AND

CERVICIS

INTERMEDIATE - ERECTOR SPINAE

DEEP - TRANSVERSOSPINAL

MUSCLES OF THE ABDOMINAL

WALL

LINEA ALBA RECTUS

ABDOMINIS

PYRAMIDALIS

ABDOMINAL MUSCLES FORM THE ABDOMINAL

WALL THAT PROTECTS AND SUPPORTS THE

ABDOMINAL VISCERA

THEY FLEX AND ROTATE THE TRUNK (AS IN SIT-

UPS)

COMPRESS THE ABDOMEN IN FORCED

EXPIRATION

CONTRACTION OF THE ABDOMINAL

MUSCULATURE, WITH THE DIAPHRAGM WHEN

THE GLOTTIS (OPENING TO TRACHEA) IS

CLOSED, GREATLY INCREASES INTRA- ABDOMINAL PRESSURE VALSALVA MANUVER -

NECESSARY FOR URINATION, DEFECATION,

CHILDBIRTH, COUGHING, VOMITING, ETC.

ABDOMINAL MUSCLES:

3 HORIZONTAL OR OBLIQUE

EXTERNAL ABDOMINAL OBLIQUE

INTERNAL ABDOMINAL OBLIQUE

TRANSVERSE ABDOMINAL

1 VERTICAL MUSCLE

RECTUS ABDOMINIS

1 VERY SMALL TRIANGULAR MUSCLE

PYRAMIDALIS

RECTUS ABDOMINIS

VERTICAL BAND-LIKE

MUSCLE, PAIRED

SEPARATED BY THE

LINEA ALBA

COVERED ANTERIORLY

AND POSTERIORLY BY

THE RECTUS SHEATH

CONTAINS TENDINOUS

INTERSECTIONS - 3 OR

MORE TRANSVERSE

LINES - FORMS “6-

PACK”

INTERMEDIATE DISSECTION OF THE

ABDOMEN

RECTUS SHEATH REMOVED ON LEFT

SIDE; NOTE

TENDINOUS

INTERSECTIONS

EXTERNAL OBLIQUE

MOST SUPERFICIAL OF

THE 3 OBLIQUE OR

HORIZONTAL

ABDOMINAL MUSCLES

FIBERS RUN DOWN AND

INWARD

INSERTS INTO THE LINEA

ALBA

INFERIOR EDGE FORMS

INGUINAL LIGAMENT - MEDIAL EDGE IS THE INGUINAL LIGAMENT

SUPERFICIAL INGUINAL

RING

INTERNAL OBLIQUE

INTERMEDIATE LAYER OF 3 FLAT

MUSCLES

UPPER FIBERS RUN

SUPERIORLY,

MIDDLE FIBERS RUN

HORIZONTALLY,

LOWER FIBERS RUN

INFERIORLY

INSERTS INTO THE

LINEA ALBA

TRANSVERSE ABDOMINIS

INNER MOST LAYER

FIBERS RUN

HORIZONTALLY

INSERTS INTO LINEA

ALBA

RECTUS

ABDOMINUS

EXTERNAL

OBLIQUE

TENDINOUS

INTERSECTION

PYRAMIDALIS

INTERNAL

OBLIQUE

SUPERFICIAL

RECTUS SHEATH INGUINAL RING

INGUINAL HERNIAS - A PROTRUSION OF SOME VISCERAL STRUCTURE THROUGH A NORMAL OR

ABNORMAL OPENING IN THE ABDOMINAL WALL

90% OF ABDOMINAL HERNIAS ARE IN THE

INGUINAL REGION

75% ARE CALLED INDIRECT OR CONGENTIAL

HERNIAS (THROUGH THE SUPERFICIAL INGUINAL

RING)

20X MORE COMMON IN MALES

DIRECT HERNIAS OCCUR THROUGH A WEAK SPOT

IN THE ABDOMINAL WALL