SCRUFF is a term used to describe the back of the neck and the area around it. SCUM is an acronym for 'Subcutaneous Ulnar Musculature, ' which is the muscle located at the back of the neck. NAPE stands for 'Nuchal Area Posterior Extension, ' which is the area at the back of the neck that extends down the spine. Together, SCRUFF is a term used to describe the back of the neck and the area around it, including the subcutaneous ulnar musculature and the nuchal area posterior extension.