- Origin
- Lateral 1/3rd of the Inguinal Ligament
- Anterior 2/3rds of the inner lip of the Iliac Crest
- Lumbar Fascia
- 11 and 12th Rib
- Inner aspects of the lower 6 Costal Cartilages (where it interdigitates with the diaphragm)
- Insertion
- Conjoint Tendon
- Xiphoid Process
- Linea Alba
- Pubic Crest
- Muscle fibres become aponeurotic and pass behind the Rectus Abdominis to fuse with the Internal Oblique aponeurosis in the Linea Alba
- Below Arcuate Line, aponeurosis passes wholly in front of the Rectus Abdominis
- In upper part of abdomen, the outer margin of the aponeurosis is more medial; muscular fibres lie behind the lateral part of the Rectus Abdominis
- Lower fibres of aponeurosis curve downwards and medially with those of the Internal Oblique as the Conjoint Tendon – inserting on the Pubic Crest and Pectineal Line