Thoracic and Lumbar Muscles Flashcards
O/I/A Internal Oblique
O: lateral 2/3rd of inguinal ligament, anterior 2/3rd of iliac crest and thoracolumbar facia
I: Inferior border of lower 4 ribs (8-12)
A: Both sides flex, 1 side side flexes and rotates to SAME side
O/I/A External Oblique
O: outer border of lower 8 ribs and costal cartilages (4-12)
I: lateral 2/3rd of iliac crest and joins other side of linea alba
A: both flex the spine, 1 side flexes to SAME side and rotates to OPPOSITE side
O/I/A Rectus Abdominus
O: front of pubis and pubic crest
I: xiphoid process and costal cartilages of ribs 5-7
A: flexes trunk
O/I/A Transverse Abdomen
O: lateral 1/3rd iguinal ligament, anterior 2/3rd iliac crest and lower 6 ribs (6-12)
I: Linea alba in midline
A: keeps abdominal tone for organs (deepest core muscle)
O/I/A Quadratus Lumborum
O: ilio lumbar ligament, adjacent to iliac crest
I: medial 1/2 of 12th rib and TP’s of lumbar vertebrae L1-L4
A: Both- extend One- SAME side flexion Hip hike
O/I/A Multifidus
O: Sacrum, PSIS, iliac crest
I: SP’s of vertebrae
A: extesnion, stabiliser
O/I/A Psoas Major
O: TP’s and vertebral bodies of T12-L5
I: Inguinal ligament and lesser trochanter of femur
A: Flexion, trunk stabilisation
O/I/A Psoas Minor
O: Lateral surface of T12 and L1
I: iliopubial (iliopectinal) eminence
A: flexion
O/I/A Upper trapezius
O: external occpital protuberance, superior nuchal line and nuchal ligament
I: lateral 1/3rd of clavicle, acrominion
A: stabilise and move the scapula, shoulder raise
O/I/A Middle trapezius
O: SP’s of T1-T4
I: acromion, spine of scapula
A: abduct and retract the scapula
O/I/A Lower trapezius
O: SP’s T4-T12
I: medial part of spine of scapula
A: depression
O/I/A Serratus Anterior
O: supereolateral surfaces of ribs 1-8
I: medial border of scapula
A: protraction
O/I/A Pectoralis major
O: medial 1/2 of clavicle, sternum, costal cartilages of ribs 1-6
I: gretaer tubercle of huemrus
A: scapula protraction, arm adduction and internal rotation
O/I/A Pectoralis minor
O: costal cartilages of ribs 3-5
I: coracoid process
A: scaupla protraction
what is the function of the diaphragm?
Faciliates breathing
Contraction increases the throacic volume- inhalation
Relaxation decreases the thoracic volume- exhalation
what is the diaphragm?
a dome shaped muscle that separates the thoracic and abdominal cavities
what muscles facilitate breathing?
the diaphragm, internal inetrcostals and scalene
how do internal intercostal muscles facilitate breathing?
they aid active exhalation as when they contract it causes depression of the rib cage which therefore causes a decrease in the thoracic cavity volume
how do exetrnal intercostal muscles facilitate breathing?
they elevate the ribs during forced inspiration.
This increases the thoracic cavity volume and facilitates entry of air into the lungs.
O/I/A of latissimus dorsi
O: SP’s of T7-T12, iliac crest and thoracolumbar facia
I: sulcus of humerus
A: assist in respiration by elevating and depressing the ribs
adducts and interanlly rotates the arm
