Musculus transversus abdominis
The transversus abdominis is the deepest abdominal muscle, with fibers running transversely. It originates from the transverse processes of the lumbar vertebrae, the medial surfaces of the last several ribs, and the tuber coxae. It inserts on the linea alba via a broad aponeurosis. Its actions are to compress the abdomen, support the viscera, assist expiration, and provide core stabilization. The costal portions interdigitate with the diaphragm. It is innervated by ventral branches of thoracic and lumbar spinal nerves.
Origin: Transverse processes of lumbar vertebrae, medial surfaces of the last several ribs, and tuber coxae
Insertion: Linea alba via broad aponeurosis
Action: Compresses the abdomen; supports viscera; assists expiration; core stabilization
Innervation: Ventral branches of thoracic and lumbar spinal nerves
Relevant in evaluations of core stability, abdominal wall integrity, and back support. Dysfunction can contribute to reduced core strength and performance issues. Diagnosis is clinical.
## Overview Core weakness reduces the ability of the deep trunk muscles to stabilize the spine. This increases shear and compressive forces on the back, contributes to kissing spines discomfort, musc
## Overview An abdominal wall hernia is a defect in the body wall that allows abdominal contents to protrude under the skin. It appears as a soft swelling that may enlarge with straining. Post-foalin
Persistent abdominal weakness or reduced core engagement should be evaluated. Balanced work and correct conditioning support core strength.
## Overview Core weakness reduces the ability of the deep trunk muscles to stabilize the spine. This increases shear and compressive forces on the back, contributes to kissing spines discomfort, muscle fatigue, and poor posture, and can perpetuate a cycle of pain and further weakness. ## Causes Disuse, pain inhibition, poor training, or prolonged stall rest. ## Diagnosis Visual and palpatory assessment of topline and abdominal tone plus functional tests of stability. ## Treatment Progressive core-strengthening program combined with treatment of any primary back pathology. ## Recovery and Prognosis Good with consistent rehabilitation. ## Prevention Include core work in regular conditioning. Signs include: poor topline muscling; hollow or swayed back posture; fatigue under saddle; back sensitivity
## Overview An abdominal wall hernia is a defect in the body wall that allows abdominal contents to protrude under the skin. It appears as a soft swelling that may enlarge with straining. Post-foaling mares are at higher risk from prepubic tendon or muscle rupture. Most are not painful unless the contents become strangulated. ## Causes Trauma, foaling injury, or surgical incision failure. ## Diagnosis Palpation of a reducible swelling and ultrasound confirming the body-wall defect and contents. ## Treatment Small, stable hernias may be monitored. Larger or enlarging hernias, and any with signs of strangulation, require surgical repair. ## Recovery and Prognosis Good for uncomplicated repairs. Strangulated hernias are emergencies with a more guarded outlook. ## Prevention Careful management of post-foaling mares and proper surgical technique. Signs include: soft swelling on the ventral abdomen; may enlarge with straining; usually not painful unless strangulated; higher risk in post-foaling mares
Relevant in evaluations of core stability, abdominal wall integrity, and back support. Dysfunction can contribute to reduced core strength and performance issues. Diagnosis is clinical.
Persistent abdominal weakness or reduced core engagement should be evaluated. Balanced work and correct conditioning support core strength.
See the Transversus Abdominis on our interactive 3D horse model. Open 3D Model