The tendinous inscriptions of the rectus abdominis muscle are not attached to the posterior lamina of the rectus sheath
This means that local anaesthetic injected between the rectus abdominis muscle and the posterior lamina in theory can spread along the backside of the rectus abdominis muscle and anaesthetize the anterior cutaneous branches of the 9th, 10th and 11th intercostal nerves
Rectus abdominis muscle with tendinous inscriptions (magenta arrows), umbilicus (blue arrow), and linea alba (red asterix)
