Muscles moving the Axial Skeleton

Muscles moving the Axial Skeleton

1. Muscles of the neck

   • Anterior Neck
     • Sternocleidomastoid
       • Runs from the medial clavicle and manubrium to the mastoid process
       • Flexion of cervical spine
       • Contralateral rotation
       • Ipsilateral lateral flexion
   • Posterior Neck
     • Splenius muscles (cervicis, capitis)
       • Cervicis - runs form spinous process of of T3-T6 to transverse process of C1-C3
       • Capitis - runs from spinous process C7, T1-T4 to mastoid process and occipital bone
       • Cervical extension
       • Ipsilateral rotation and lateral flexion

2. Muscles of the trunk

   • Anterolateral Abdominal Wall
     • Structure
       • Bilaterally paired muscles
       • 3 flat muscles
         • External Obliques
         • Internal Obliques
         • Transverse Abdominis
       • 1 vertical muscle
         • Rectus Abdominis
     • External Obliques
       • Most superficial of the three lateral muscles
       • runs from the ribs to the pelvis and abdominal aponeurosis to the line alba
       • compresses the abdomen
       • laterally flexes the vertebral column
       • contralateral rotator of the trunk
     • Internal Obliques
       • middle layer of the three lateral abdominal muscles
       • posterior fibres pass from the anterior trunk to the lumber spine
       • compresses the abdomen and stabilises the spine
       • ipsilateral rotator of the trunk
     • Transverse Abdominus
       • Deepest of the three lateral abdominal muscles
       • passes from the anterior trunk to the lumbar spine
       • compresses the abdomen and stabilises the spine
       • TrA becomes active prior to limb movement
       • Co-contract with multifidis
   • Rectus Abdominis (RA)
     • Runs from the pelvis to the ribs and sternum
     • RA and lateral fibres of the external obliques prime movers of trunk flexion
     • mobilisers
     • better set up for rapid ballistic movements
   • Posterior Trunk Muscles
     • Quadratus Lumborum
       • Posterior abdominal wall
       • Often forgotten
       • Forms an important part of the corset
       • Runs from the pelvis to the 12th rib and lumbar vertebrae
       • Actions include lateral flexion and extension of the lumbar spine
     • Erector Spinae muscles
       • includes iliocostalis, longissimus and spinals muscles
       • Runs from iliac crest and sacrum to insertion points up to C2
       • Main action is trunk and neck extension
     • Lumbar Multifidus
       • Cover a small number of spinal segments
       • Helps to stiffen the spine prior to limb movement
       • Co-contraction with TrA

3. Nerve supply

   • External Oblique
     • T8-12
     • L1
   • Internal Oblique
     • T8-12
     • L1
   • Transverse Abdominis
     • T8-12
     • L1
   • Rectus Abdominis
     • T7-12
   • Quadratus Abdominis
     • T12 - L1/3
   • Erector Spinae
     • Adjacent spinal nerves
   • Multifidus
     • Adjacent spinal nerves

4. Functional classification of core muscles

   • Stabilising and Movement systems
     • Local muscles
       • Primary
         • Transverse Abdominis
         • Multifidus
       • Secondary
         • Internal obliques
         • Medial fibres of external obliques
         • Quadratus lumborum
         • Diaphragm
         • Pelvic floor muscles
         • Iliocostalis and Longissimus (lumbar portion)
     • Global muscles
       • Rectus Abdominis
       • Lateral fibres of external obliques
       • Psoas major
       • Erector spine
       • Iliocoastalis (thoracic portion)
   • Characteristics of the Stabilising and Movement systems
     • Local
       • Deeply placed
       • Aponeurotic
       • Slow-twitch nature
       • Active in endurance activities
       • Selectively weaken
       • Poor recruitment, may be inhibited
       • Activated at low resistance levels
       • Lengthen
     • Global
       • Superficial
       • Fusiform
       • Fast-Twitch nature
       • Active in power activities
       • Shorten and tighten
       • Activated at higher resistance levels