Validity and reliability of two Smartphone applications to measure the lower and upper cervical spine range of motion in subjects with chronic cervical pain

BACKGROUND: Cervical pain is the biggest musculoskeletal health problem in industrialised countries. There is an important association between this and decrease in range of motion. OBJECTIVE: Estimate the validity and reliability intra and inter examiner of two Smartphone apps regarding the measurement of lower and upper cervical spine range of motion in subjects with chronic cervical pain. METHODS: A cross-sectional study was conducted. The sample consisted of 25 subjects with chronic cervical pain. An examiner made a measurement of the range of motion using the CROM device as a gold standard, afterwards, another examiner did the same using a Smartphone, in order to establish validity. After this, the Smartphone examiner and a new examiner simultaneously conducted the intra and inter examiner reliability. RESULTS: Measurement of the lower and upper cervical spine range show an excellent validity (> 0.75), with an excellent intra and inter reliability (> 0.75) in all movements except flexion of upper cervical spine (0.75–0.65). CONCLUSION: The two Smartphone applications used in this study showed an excellent validity compared to the CROM. The intra and inter reliability is excellent for all movements, except for the upper cervical spine flexion