Internal abdominal oblique muscle

Internal Abdominal Oblique Muscle

The Internal Abdominal Oblique Muscle is a key component of the human abdominal wall. It lies beneath the External Abdominal Oblique Muscle and just above the Transversus Abdominis Muscle, playing a crucial role in respiratory movements, supporting the abdominal viscera, and aiding in the mechanical process of digestion.

Anatomy

The Internal Abdominal Oblique Muscle originates from the thoracolumbar fascia of the lower back, the iliac crest of the pelvis, and the inguinal ligament. It inserts into the linea alba, the pubic crest, and the ribs, specifically the lower three or four, with its fibers running "upward and medially." This orientation is perpendicular to the External Abdominal Oblique Muscle, which it lies beneath.

Function

The primary functions of the Internal Abdominal Oblique Muscle include:

• Assisting in forced respiration by aiding in the process of exhalation and, to a lesser extent, inhalation.
• Contributing to the increase of intra-abdominal pressure, which is essential for defecation, urination, childbirth, and vomiting.
• Acting in unison with its counterpart on the opposite side, it helps in trunk rotation and lateral flexion of the vertebral column.

Clinical Significance

Injury to the Internal Abdominal Oblique Muscle can result in pain, reduced mobility, and difficulty performing tasks that involve trunk rotation or lateral flexion. Such injuries are often seen in athletes and may require physical therapy for rehabilitation.

Surgical and Diagnostic Relevance

The Internal Abdominal Oblique Muscle is often involved in surgical procedures, particularly in the repair of hernias. Its anatomical position makes it a landmark in various diagnostic and therapeutic interventions in the abdominal and pelvic regions.