Trunk muscles Flashcards
Rhomboids
O: Minor C7-T1 Major T2-T5 I: Medial border of scapula Action: Retraction and medial rotation of shoulder girdle. Scapular elevation and stabilisation
External oblique
O: Lower 8 ribs (5-12)
I: Anterior iliac crest, linea alba via abdominal aponeurosis
Action: Trunk rotation and flexion
Internal oblique
O: Lower 3-4 ribs (9/10-12)
I: Lateral 1/3 of inguinal ligament, thoracolumbar fascia, iliac crest, linea alba via abdominal aponeurosis
Action: Trunk rotation and flexion
Psoas major
O: Bodies and TPs of L1-L5
I: Lesser trochanter
Action: Hip and trunk flexion.
Anterior pelvic tilt.
Erector spinae
Spinalis, longissimus and iliocostalis
Spinalis: SPs of C7-T12, ligamentum nuchae
Longissimus: TPs of C2-T12, mastoid process, lower 9 ribs (4-12), sacrum?
Iliocstalis: iliac crest, ribs 1-12, TPs C5-7 and L1-3, sacrum?
Action: Trunk and cervical extension. Lateral flexion.
Multifidus & rotatores
O: TPs of C2-L5
Multifidus only: sacrum
I: SPs C2-L5 (Mulitifidus spans 2-4 and rotatores 1-2 vertebrae)
Action: Extension and rotation of vertebral column
Quadratus lumborum
O: Posterior iliac crest
I: Bottom rib, TPs L1-L4
Action: Trunk extension and side flexion
Semispinalis
Capitis, cervicis and throacis
O: TPs C1-T10
I: Nuchal line, SPs C2-T4,
Action: Trunk rotation, cervical extension and rotation
Serratus anterior
O: Ribs 1-8/9
I: Medial border of scapula
A: Protracts, depresses and upwardly rotates scapula. Fixes medial border to rib cage
Latissimus Dorsi
O: Inf angle of scapula, SPs T7-12, Ribs 10-12, thoracolumbar aponeurosis, posterior iliac crest
I: Floor of intertubercular groove
A: Extends, adducts and medially rotates shoulder
Pectoralis major
O: Medial 1/2 of clavicle, manubrium and body of sternum, costal cartilage of ribs 1-6
I: Lateral lip of intertubercular groove
A: Shoulder adduction and medial rotation
Upper fibres flex, lower fibres extend shoulder
Pectoralis minor
O: Ribs 3-5
I:. Coracoid process
A: Scapula protraction (also deprress and downwardly rotate_
Rectus abdominus
O: Pubic crest, pubic symphysis
I: Xiphoid process, costal cartilage ribs 5-7
A: Trunk flexion, posterior pelvic tilt
Diaphragm
O: Post. surface of xiphoid process, lower 6 ribs (7-12) and their costal cartilage, L1-L3 vertebral bodies
I: Central tendon
A: Draws down central tendon to increase volume of thoracic cavity
Transverse Abdominus
O: Lat inguinal ligament, anterior 2/3 of iliac crest, thoracolumbar fascia, internal surface of lower 6 ribs (7-12)
I: Linea alba via abdominal aponeurosis
A: Compresses abdomen
