Midcavicular line: 6-8th ribs
Midaxillary line: 8-10th ribs
Paravertebral line: 10-12nd ribs
So physician must insert a needle in 8-10th ribs in midaxillary line; but insertion below the 9th rib still has a risk to damage abdominal organs such as liver. Upper border of 9th rib is fine.
Uw question ID: 844
Inserting the needle into the 9th intercostal space, midaxillary line during expiration will avoid the inferior border of the lung.