Serratus posterior inferior muscle

The serratus posterior inferior muscle is a broad irregular-shaped back muscle that lies underneath the latissimus dorsi muscle. It is positioned in the lower back at the junction of the thoracic and lumbar regions. The serratus posterior inferior extends between the lower thoracic vertebrae and upper lumbar vertebrae and lower ribs. It is larger than the serratus posterior superior muscle. Both serratus posterior muscles are located relatively far from each other.