lecture 12 Abdominal and back muscles Flashcards
morphology of vertrbrae
cervicle
thorastic
lumbar
anatomy of the spine
vertebrae:
7 cervicle
12 thoracic
5 lumbar
sacrum (5 segments)
coccyx (4 segments)
intervertebral joints
articulations between adajacent vertebral bodies
type: cartlidogenous
2-3 degrees
less movement than synovial
dependent on dish size
movements of the spine
extension/ flexion
lateral flexion/ lateral flexion
rotation of the neck and head/ rotation of the upper trunk
movement of the cervicle spine
flexion/ extension, lateral flexion, rotation
what joints do the movements of the cervicle spine occur at
atlanto- occipital joint
atlanto- axial joint
muscles of the neck
scalenes
sternocleidomastoids
sternocleidomastoid
origin
insertion
innervention
actions
*Origin: Manubrium and medial portion of
the clavicle
*Insertion: Mastoid process of the
temporal bone, superior nuchal line.
*Innervation: Accessory Nerve (CN XI)
*Actions: (Unilaterally) contralateral
cervical rotation, ipsilateral flexion of the
cervical spine
*(Bilaterally): cervical flexion, assist with
forced exhalation by elevating the sternum
scalnes
origin
insertion
actions
*3 Muscles (Ant., Middle and
Post.)
*Origin: Cervical Vertebrae (C2 – C7)
*Insertion: First and Second Ribs
*Actions: Elevation of the first and
second ribs. Lateral Flexion of the
Neck. Assists with forced inhalation
erector spine
illiocotalis (origin illiac crest)
longissimus (longest muscle)
spinalis (musle down the spinous process)
“i love spine”
spinalis
most medial
extends vertbral column
longissimus
middle group
extends and laterally flexes vertebral column
iliocostalis
most lateral group
extends amd laterally flexes the vertebral column
thoracic portion of iliocostalis & longissimus
75% slow-twitch fibres
Line of action parallel to
spine
Greatest mechanical
advantage for extension
Function?
Extension
type 1
mitchondria dominated= actiavted long time without fatigue
used to stand or sit up right due to gravity to sustain fuel source
composed of mainly slow twitch fibers
netural lumbar spine
resistance to anterior shear provides acceptable levels of compression
flexed lumbar spine
(coming back into extension)
no resistnce to anterior shear provides excessive levels of compression
origin
insertion
action
-all erector spinae muscles have the same fucntion:
extension of verterbral column (bilateral)
-maintance of erect posture (bilateral)
-stabilization of vertbral column during flexion (bilateral)
-lateral bend to the same side (unilateral)
-opposite side contracts to stablize eccentrically (unilateral)
nerve supply to the errector spine
posterior root ganglion
anterior root
posterior ramus
muscles of the back
multifidus
-span only a few verterbrae
extension BUT forces affect only local areas of the spine. Therefore, provide ability for corrections at specific joints
- Rotatores
- Usually described as ‘rotators’ of
the spine. - But so small that contribution to
twisting is limited - Instead, have a proprioception
function
quadratus lumborum
Origin: Iliac crest and Illiolumbar
ligament
Insertion: base of 12th rib and
transverse processes of the lumbar
vertebrae
Actions: (Unilaterally) lateral flexion
of the vertebral column
(Bilaterally): depression of the rib
cage
*Special functions: Research has
shown that the length the muscle
remains fairly constant when
activated. Thought to help stabilize
the lumbar spine.
muscles of the abdominal wall rectus abdominis
rectus abdominis
Origin: Crest of the
pubis
Insertion: Costal
cartlidges of ribs 5-7,
xiphod process
Innervation: thoraco-
abdominal nerves (T7-
T11) and subcostal
nerve (T12)
Actions: Flexion of the
Lumbar Spine
external obliques
external oblique
Origin: Ribs 5-12
Insertion: Illiac crest, pubic
tubercle, Linea alba
Innervation: Thoracoabdominal
nerves (T7-11) and subcostal nerve
(T12)
Actions: Contralateral rotation of
torso
* Note fibre direction
internal obliques
Origin: Inguinal ligament, iliac crest
and the lumbodorsal fascia
Insertion: linea alba, and ribs 10-12
Innervation: Thoracoabdominal nn.
(T7-T11), Subcostal n. (T12),
Iliohypogastric n. (L1) and Ilioinguinal
n. (L1)
Actions: (Unilaterally) ipsilateral
trunk rotation
(Bilaterally): compresses abdomen
* Note fibre direction
Internal Obliques
External Oblique
transverse abdominus
Origin: Iliac crest, inguinal ligament,
thoracolumbar fascia, and costal
cartilages 7-12
Insertion: Xiphoid process, linea
alba, pubic crest
Innervation: Thoracoabdominal nn.
(T7-T11), Subcostal n. (T12),
Iliohypogastric n. (L1) and Ilioinguinal
n. (L1)
Actions: compresses abdominal
cavity
* Note fibre direction
