Musculus iliocostalis
The iliocostalis is the most lateral member of the erector spinae group. It originates from the lumbar fascia and lumbar transverse processes and inserts on the angles of the ribs and the transverse processes of C7. Its actions include lateral flexion of the spine and elevation of the ribs to assist inspiration. It is innervated by the dorsal branches of the thoracic and lumbar spinal nerves. It contributes to trunk stability and respiratory mechanics, especially during exercise.
Origin: Lumbar fascia and lumbar transverse processes
Insertion: Angles of the ribs and transverse processes of C7
Action: Laterally flexes the spine; assists inspiration by elevating the ribs
Innervation: Dorsal branches of thoracic and lumbar spinal nerves
Rarely a primary source of pathology. It may be involved secondarily in back strain or increased respiratory effort.
## Overview Rib-region muscle pain involves the muscles along the rib cage that are loaded during lateral work, tight circles, and jumping. Strain produces girthiness, stiffness on one rein, reluctan
## Overview Rib fracture guarding is protective muscle spasm around a fractured rib. The horse breathes shallowly, resists girthing on the affected side, and may appear colicky because chest pain mim
Back stiffness or reduced lateral flexibility is more often related to other structures. This muscle is part of the overall supporting system.
## Overview Rib-region muscle pain involves the muscles along the rib cage that are loaded during lateral work, tight circles, and jumping. Strain produces girthiness, stiffness on one rein, reluctance to bend through the rib cage, and skin twitching when the area is palpated. ## Causes Overuse or acute strain during lateral movements. ## Diagnosis Palpation and observation of lateral flexibility. ## Treatment Rest, physiotherapy, anti-inflammatories, and gradual return to lateral work. ## Recovery and Prognosis Good. ## Prevention Progressive training of lateral movements and correct saddle fit. Signs include: girthiness; stiffness on one rein; reluctance to bend through the rib cage; skin twitching on palpation; difficulty with lateral movements
## Overview Rib fracture guarding is protective muscle spasm around a fractured rib. The horse breathes shallowly, resists girthing on the affected side, and may appear colicky because chest pain mimics abdominal pain. Localized swelling and pain are present. ## Causes Rib fracture from kick or fall. ## Diagnosis Palpation and imaging of the ribs. ## Treatment Pain relief and rest. The guarding resolves as the fracture heals. ## Recovery and Prognosis Good for uncomplicated fractures. ## Prevention Trauma avoidance. Signs include: localized pain and swelling over the rib; shallow breathing; resistance to girthing; may mimic colic
Rarely a primary source of pathology. It may be involved secondarily in back strain or increased respiratory effort.
Back stiffness or reduced lateral flexibility is more often related to other structures. This muscle is part of the overall supporting system.
See the Iliocostalis on our interactive 3D horse model. Open 3D Model