Serratus posterior is a muscle group located on the back. This muscle connects the 12th rib and the lower thoracic vertebrae to the muscles that connect the shoulder blade. The name serratus posterior comes from the Latin word "serratus," meaning "serrated" or "saw-toothed." There are several synonyms for serratus posterior, including "serratus posterior inferior," "serratus posterior superior," and "serratus dorsalis." All of these terms describe the same muscle group, but they refer to the specific location of the muscles within the back. Knowing these synonyms can be helpful when studying anatomy or discussing back pain or injuries with your healthcare provider.