Nowadays, smartphone technology provides opportunities for assessing and treating patients in clinical facilities and during the follow-up of the patient's progress. To date, many studies have assessed the validity and reliability of the smartphone application against universal goniometer for various joint motions, for instance, the spinal column, knee, and ankle. This study aims to determine the validity and reliability of smartphone inclinometer application for measurement of cervical region range of motion.

Inclusion Criteria:

• Adults aged 18 to 33 years.
• Both genders.
• Subjects that are cooperative to follow my instructions

Exclusion Criteria:

• Subjects with severe spinal pathology.
• Pregnancy and lactation.
• Any musculoskeletal diseases that affect the cervical spine.
• Any neurological diseases that affect the cervical spine.
• History of trauma in the cervical spine.
• Signs of cervical radiculopathy.
• Signs of cervical myelopathy.
• Signs of serious pathology.
• subjects have a pacemaker or any other medical equipment that the magnet might have compromised.