Abdominal external oblique muscle

Illu trunk muscles

Abdominal External Oblique Muscle

The Abdominal External Oblique Muscle is a large, thin, muscular layer of the abdomen that forms part of the abdominal wall. It is situated on the lateral and anterior parts of the abdomen. This muscle is the most superficial of the three flat muscles of the abdominal wall, the other two being the Internal Oblique Muscle and the Transversus Abdominis Muscle.

Anatomy

The Abdominal External Oblique Muscle originates from the lower eight ribs, interdigitating with the Serratus Anterior Muscle and the Latissimus Dorsi Muscle. Its fibers run diagonally downward and medially, inserting into the Linea Alba, Pubic Tubercle, and the anterior half of the Iliac Crest. The muscle's fibers form aponeuroses as they descend, which contribute to the formation of the Inguinal Ligament.

Function

The primary function of the Abdominal External Oblique Muscle is to assist in the lateral flexion and rotation of the trunk. When both sides of the muscle contract simultaneously, they aid in abdominal compression, contributing to functions such as forced expiration, coughing, and defecation. Additionally, this muscle plays a crucial role in maintaining posture and supporting the abdominal viscera.

Clinical Significance

Injuries to the Abdominal External Oblique Muscle can occur due to overuse, sudden twists, or direct trauma. Symptoms of an injury include pain, swelling, and a decrease in the strength of the abdominal wall. Hernias, particularly Inguinal Hernias, can also involve the Abdominal External Oblique Muscle due to weaknesses in the abdominal wall.

Exercise and Strengthening

Exercises targeting the Abdominal External Oblique Muscle include side planks, Russian twists, and bicycle crunches. Strengthening this muscle can improve core stability, reduce the risk of injury, and enhance athletic performance.

See Also

• Abdominal Muscles
• Core (anatomy)
• Inguinal Canal
• Hernia