Spigelian hernias usually occur:A. On the lateral border of the rectus abdominis muscle
Spigelian hernias can occur anywhere along the length of the Spigelian line or zone-an aponeurotic band of variable width at the lateral border of the rectus abdominis. The most common location of these rare hernias is at the level of the arcuate line. These hernias are not always apparent on physical examination, and may cause local pain or incarceration.