Neck Disability Index

The Neck Disability Index (NDI) is a 10-item patient-reported outcome measure assessing the impact of neck pain and dysfunction on daily activities and quality of life. Developed by Vernon and Mior in 1991, NDI is the most widely used outcome measure in neck pain research and clinical practice, applicable to acute whiplash, cervical radiculopathy, chronic neck pain, and post-operative cervical conditions.