A Study on the Validity and Test-retest Reliability of the Measurement of the Head Tilt Angle of the Smart Phone Application ‘KPIMT Torticollis Protractor’

ABSTRACT

Purpose@#The purpose of this study was to compare the concurrent validity and test-retest reliability of ‘KPIMT Torticollis Protractor’, a smart phone and I-pad application for convenient range of motion measurement, and ‘Image J’, an analysis software with high reliability and validity, according to head tilt and active cervical rotation angle. This was done to determine the clinical utility of ‘KPIMT Torticollis Protractor’. @*Methods@#Head tilt and active cervical spine rotation angles of 40 children with congenital muscular torticollis were measured using Image J and KPIMT Torticollis Protractor, respectively. The level of concurrent validity and inter-rater and intra-rater reliability between the two measurement methods were analyzed. @*Results@#For forty participants, the concurrent validity between Image J and KPIMT Torticollis Protractor showed very high validity with ICC of ICC 0.977 (0.995-0.999), 0.994 (0.994-0.998), CVME% 0.71-0.72%, SEM% 0.31-0.34%, MDC% 0.86-0.94%. The test-retest intra-rater reliability showed very high reliability ICC 0.911 (0.911-0.966), CVME% 0.71%, SEM% 0.34-0.36%, MDC% 0.81-0.94%. The test-retest inter-rater showed very high reliability ICC 0.936 (0.933-0.957), CVME% 0.70%, SEM% 0.34-0.35%, MDC% 0.81-0.83%. @*Conclusion@#The KPIMT Torticollis Protractor, a smart phone and IPD application, is a highly reliable and valid device for angle measurement in children with congenital myotonia and can be easily used in clinical practice.