M. transversus abdominis, digitatio costalis III
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: Medial surface of costal cartilage of rib 9
Insertion: Linea alba via aponeurosis
Action: Compresses abdominal viscera; supports visceral weight; assists forced expiration
Innervation: Ventral branches of thoracic (T10–T18) and lumbar (L1–L3) 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 Strain or tearing of the transversus abdominis, the deepest abdominal muscle, occurs from sudden exertion, rolling, or trauma. Because it is deep, injuries can be hard to detect. Signs in
Persistent abdominal weakness or reduced core engagement should be evaluated. Balanced work and correct conditioning support core strength.
## Overview Strain or tearing of the transversus abdominis, the deepest abdominal muscle, occurs from sudden exertion, rolling, or trauma. Because it is deep, injuries can be hard to detect. Signs include focal pain on deep flank palpation, guarding during lateral flexion, ventral edema, and ultrasound evidence of fiber disruption or hematoma. ## Causes Sudden exertion or trauma. ## Diagnosis Deep palpation and ultrasound. ## Treatment Rest and anti-inflammatories. Large hematomas may need drainage. ## Recovery and Prognosis Good for most strains. ## Prevention None specific. Signs include: focal pain on deep palpation of the flank; guarding during lateral flexion; ventral edema; ultrasound fiber disruption or hematoma
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.
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