Equine dorsal trunk muscles

Serratus ventralis thoracis origin

First 8-9 ribs

Serratus ventralis thoracis insertion

Scapula cartilage and facies serrata of the scapula

Serratus ventralis thoracis function

Suspends the trunk, raises the neck when forelimb is fixed, may support inspiration

Serratus ventralis thoracis nerve innervation

Long thoracic nerve

Latissimus dorsi origin

Supraspinous ligament from T3 caudally via thoracolumbar fascia

Latissimus dorsi insertion

Teres major tuberosity of humerus together with teres major muscle

Latissimus dorsi function

Lateral flexion of the back, shoulder flexion, retracts the limb and draws the trunk cranially

Latissimus dorsi nerve innervation

Thoracodorsal nerve

Longissimus dorsi (capitis) origin

Transverse processes of T1-2

Longissimus dorsi (capitis) insertion

Wing of atlas

Longissimus dorsi (capitis) function

Extends back and neck, stabilises vertebral column

Longissimus dorsi (capitis) nerve innervation

Dorsal branches of local spinal nerves

Longissimus dorsi (atlantis) origin

Transverse processes of  T1-2, articular processes of C3-7

Longissimus dorsi (atlantis) insertion

Wing of atlas and mastoid process

Longissimus dorsi (atlantis) function

Extends back and neck, stabilises vertebral column

Longissimus dorsi (atlantis) nerve innervation

Dorsal branches of local spinal nerves

Longissimus dorsi (cervicis) origin

T2-6 tubercles of the ribs

Longissimus dorsi (cervicis) insertion

Tubercle of 1st rib, cranial transverse processes of C4-7

Longissimus dorsi (cervicis) function

Extends back and neck, stabilises vertebral column

Longissimus dorsi (cervicis) nerve innervation

Dorsal branches of local spinal nerves

Longissimus dorsi (lumborum and thoracis) origin

Wing of ilium, SPs of sacral, lumbar and thoracic vertebrae

Longissimus dorsi (lumborum and thoracis) insertion

TPs of lumbar and thoracic vertebrae

Longissimus dorsi (lumborum and thoracis) function

Extends back and neck, stabilises vertebral column

Longissimus dorsi (lumborum and thoracis) nerve innervation

Dorsal branches of local spinal nerves

Multifidus origin

Articular and mamillary processes of all vertebrae C2-sacrum

Multifidus insertion

SPs of preceding vertebrae

Multifidus function

Stabilises and twists the vertebral column and elevates the neck

Multifidus nerve innervation

Dorsal branches of local spinal nerves