Trunk Muscles Flashcards
(13 cards)
Latissimus Dorsi
PA: SPs T7-L5; thoracolumbar fascia; posterior iliac crest, median sacral crest
DA: Floor of bicipital groove of humerus
Innervation: Thoracodorsal C6,7,8
Actions: Extension, adduction, and medial rotation of humerus; CC: depresses shoulder complex
Rectus Abdominus
PA: Pubic crest, symphysis, and ligaments
DA: Xiphoid process; Costal cartilage of ribs 5-7
Innervation: Ventral Rami T6-12
Actions: Bilaterally flexes trunk; compresses abdominal viscera; posterior pelvic tilt
External Abdominal Obliques
PA: Lower 8 ribs on exterior and inferior surfaces
DA: Anterior half of iliac crest; abdominal aponeurosis to linea alba
Innervation: Ventral Rami T7-12
Actions: Bilaterally flexes trunk; compresses ab viscera; posterior pelvic til; unilaterally side-bends trunk; contra laterally rotates trunk
Internal Abdominal Obliques
PA: Lateral 2/3 inguinal ligament; anterior iliac crest; thoracolumbar fascia
DA: Lower 3-4 ribs and CC; aponeurosis to linea alba; pubic crest
Innervation: Ventral Rami T7-12
Actions: Bilaterally flexes trunk; compresses ab viscera; ipsilateral side bend and rotation of trunk; CC: posteriorly tilts pelvis
Transverse Abominus
PA: Lateral 1/3 inguinal ligament; anterior iliac crest; thoracolumbar fascia between 12th rib and iliac crest; lower 6 Costal cartilages
DA: Aponeurosis to linea alba; pubic crest
Innervation: Ventral Rami of T7-12
Actions: Compresses ab viscera; lumbar stabilization
Spinalis Thoracis
PA: SPs of T11-12 and L1-2
DA: SPs of T1-4
Innervation: Dorsal Rami of thoracic spinal nerves
Actions: Bilateral trunk extension; weak ipsilateral SB
Longissimus Thoracis
PA: Via the common tendon, thoracolumbar fascia, posterior surface of lumbar TPs; sacrum
DA: TPs of all thoracic vertebrae; lower 8-9 ribs
Innervation: Dorsal Rami of lumbar and thoracic SN
Actions: Bilateral trunk extension; ipsilateral SB
Iliocastalis thoracis
PA: Lower 6 ribs at angles
DA: Upper 6 ribs at angles
Innervation: Dorsal Rami of thoracic and lumbar SN
Actions: Bilateral trunk extension; ipsilateral SB
Multifidus
PA: TPs of lumbar through lower Cervical; sacrum; PSIS; dorsal SI ligaments
DA: SP of more superiorly located vertebra
Innervation: Dorsal Rami of corresponding level
Actions: Trunk extension; ipsilateral SB; contralateral rotation; Stabilization of SI and Lumbar joints
Quadratus Lumborum
PA: Posteromedial iliac crest; Iliolumbar ligament
DA: 12th rib along medial half of lower border; TPs of T12-L4
Innervation: Ventral Rami T12 - L3
Actions: Stabilizes 12th rib and lumbar spine; ipsilateral SB; hikes hip
Diaphragm
Attachments:
Sternal- posterior surface of xiphoid process
costal- inner surfaces of ribs 6-12
lumbar- anterior surface of L1-3
Innervation:
Motor- Phrenic nerve c3-5
Sensory- IC nerves T7-12
Actions: Primary muscle of respiration; descends during inhalation, Ascends during exhalation
External Intercostals
Attachments:
Inferior edge of Superior rib to the Superior surface of the rib below
Innervation:
Intercostals
Actions:
Respiration; most active during inspiration
Internal Intercostals
Attachments:
Inferior lateral edge of costal grooves of ribs above, to superior surface of ribs below
Innervation:
Intercostals
Actions:
Respiration; active in forced expiration
