The Neck Disability Index is reliable and validated in the Italian language, it was originated in 1991 as an adaptation of the Oswestry Disability Index, thanks to the collaboration of Howard Vernon and Silvano Mior. It is a self-administered questionnaire consisting of ten sections. For each section there are six response options with a score ranging from 0 (no disability) to 5 (full disability). Adding up the cores for the various sections gives the total score, which is interpreted as follows: 0 to 4 = no disability, 5 to 14 = mild disability, 15 to 24 = moderate disability, 25 to 34 = severe disability, and a score greater than 34 indicates complete disability.