- Origin
- Whole length of Lumbar Fascia
- Anterior 2/3rds of the Iliac Crest
- Lateral 2/3rds of the Inguinal Ligament
- Insertion
- Course: From Lumbar Fascia, muscle fibres run upwards along costal margin
- Become aponeurotic at the tip of the 9th costal cartilage
- Below costal margin, aponeurosis splits around Rectus Abdominis – two layers rejoining at Linea Alba
- Free lower border – arches over the spermatic cord
- Lateral margin: Muscle fibres in front of the cord
- Medial margin: Tendinous fibres behind the cord