The iliocostalis is a muscle located in the lower back, part of the erector spinae group. It plays a crucial role in maintaining posture and supporting the spine. The muscle extends from the lower back to the ribs, allowing for movements such as bending and twisting. This muscle is divided into three sections: iliocostalis lumborum, iliocostalis thoracis, and iliocostalis cervicis. Each section corresponds to different regions of the spine and ribs. Strengthening the iliocostalis can help improve overall back stability and reduce the risk of injury during physical activities.