Validity and Reliability Study of Head-Neck Motion and Postural Tracking Using Neck watch- A Wearable Device Prototype

This study examined the validity and reliability of an inertial measurement unit prototype, Neck Watch in measuring headneck kinematics. Head-neck kinematics was acquired simultaneously by Neck Watch and Noraxon systems in 14 healthy young adults whilst performing 4 types of movements or postures. Validity of measurement was determined using Coefficient of Multiple Correlations (CMC), Pearson’s r and Limits of Agreement (LOA), while reliability of measurements was assessed by Intra-class Correlation Coefficients (ICC). Good to excellent CMC and r values were found for standard and combined movements. Large variability for width of LOA was revealed across different movements/postures. Excellent internal consistency shown in Neck Watch indicates minimal within-subject variability. Modest to excellent ICC results found for intra- and inter-rater reliability with standard. Neck Watch prototype is valid and reliable in measuring single-plane movements. Yet, improvement is needed for recording static postures and functional movements.