Muscles Of The Trunk Flashcards
Erector spinae
Origin- pelvis
Insertion- spine, rib cage and head
Functions-
Extends the trunk, neck and head at the spinal joints
Laterally flexes the trunk, neck and head at the spinal joints
Multifidus (of transversospinalis group)
Origin- posterior sacrum, posterior iliac spine, posterior sacroiliac ligament and L5-C4 vertebrae
Insertion- spinous processes of vertebrae three- four segmental levels superior to the inferior attachment
Functions-
Extends the trunk and neck at the spinal joint
Laterally flexes the trunk and neck at the spinal joints
Contralaterally rotates the trunk and neck at the spinal joints
Quadratus lumborum
Origin- 12th rib and the transverse processes of L1-L4
Insertion- posterior iliac crest
Functions-
Elevates the same-side pelvis at the Lumbosacral joint and laterally flexes the lower lumbar spine relative to the upper lumbar spine
Anteriorly tilts the pelvis at the LS joint and extends the lower lumbar spine relative to the upper lumbar spine
Rectus abdominus
Origin- the crest and symphysis of the pubis
Insertion- xiphoid process and the cartilage of ribs 5-7
Functions-
Flexes the trunk at the spinal joints
Laterally flexes the trunk at the spinal joints
External abdominal oblique
Origin- anterior iliac crest, the pubic crest and tubercle and the abdominal aponeurosis
Insertion- the inferior border of ribs 5-12
Functions-
Flexes, laterally flexes and contralaterally rotates the trunk at the spinal joints
Internal abdominal oblique
Origin- inguinal ligament, iliac crest and thoracolumbar fascia
Insertion- ribs 10-12 and the abdominal aponeurosis
Functions-
Flexes, laterally flexes and ipsilaterally rotates the trunk at the spinal joints
Transverse abdominis
Origin- inguinal ligament, iliac crest, thoracolumbar fascia and the lower six costal cartilages of ribs 7-12
Insertion- abdominal aponeurosis
Functions-
Compresses abdominopelvic cavity
