Reliability of a laser pointer device and photogrammetry in the evaluation of cervical flexion and side bending motions

Background: There are a variety of valid instruments for range of motion measurement, including computerized photogrammetry and laser devices. However, evidence of their effectiveness in measuring cervical range of motion is limited. Objective: The purpose of the present study was to compare the reliability of photogrammetry (PG) and a laser pointer device (LPD) in the evaluation of cervical flexion and lateral bending motions in healthy subjects. Methods: In this study, thirty healthy people were recruited. Cervical flexion and inclination range were assessed by PG and an LPD. For PG evaluation, two images were recorded for each movement assessed; images were taken on the same day within a 10-minute interval to evaluate reliability. For the LPD, two measurements were taken in a longitudinal direction for cervical flexion (CF), right side bending (RSB), and left side bending (LSB). Results: PG showed high reliability for flexion and side bending movements between the two measurements CF ICC (intraclass correlation coefficient) = 0.99; RSB ICC = 0.97; LSB ICC = 0.99). Additionally, the LPD showed high reliability in all cervical movements evaluated (CF ICC = 0,99; RSB ICC = 0.99; LSB ICC = 0.99). The coefficient of variability indicated that flexion movement measurements were more homogenous in comparison to side bending movement measurements for both instruments. Conclusion: According to the results, PG and the LPD were shown to be reliable for the measurement of range of movement and the assessment of CF, RSB, and LSB in healthy people.