Cross-cultural adaptation, reliability, and validity of the Arabic version of neck disability index in patients with neck pain.

between the change in score in the NDI-Ar and global rating of change. No ceiling or fl oor effects were detected in the NDI-Ar. Conclusion. The Arabic version of the NDI has a 2-factor 10-item structure and is a reliable, valid, and responsive tool that can be used to assess neck pain in Arabic-speaking patients with neck pain. Therefore, it can be recommended for clinical and research purposes.