Document Type : Original Research


1 Department of Sport Biomechanics and Injuries, Faculty of Physical Education and Sports Sciences, Kharazmi University Tehran, Iran

2 Department of Biomechanics, Kinesiology Research Center, Kharazmi University Tehran, Iran

3 Rehabilitation Sciences Research Center, Shiraz University of Medical Sciences Shiraz, Iran

4 Department of Orthotics and Prosthetics. School of Rehabilitation Sciences. Isfahan University of Medical Sciences, Iran



Background: The development of a standard motion capture system is needed since the measurement of temporomandibular disorders is time-consuming and costly using laboratory tools. 
Objective: The current study aimed to investigate the mandibular kinematic 
variables using a regular mobile phone and the motion analysis system.
Material and Methods: In this quasi-laboratory and comparative study, ten healthy individuals participated, and three mobile cameras, nine red markers, and Kinovea software were also used to investigate the mandibular kinematic variables. Nine light reflective markers were used to check the sensitivity, accuracy, and reliability of the proposed system. The motion was analyzed using seven motion analysis infrared cameras and Qualisys Track Manager (QTM) software. Two other raters analyzed the kinematic variables obtained from the mobile to measure intra- and inter-rater reliability. 
Results: Pearson’s correlation coefficient was obtained at 0.98, 0.75, 0.98, and 0.96, showing a high correlation. The accuracy and reliability validation tests showed an average error and an accuracy of 0.156 mm and 95%, respectively, with a mobile phone. The Intra Class Correlation coefficient showed a high internal correlation in the mentioned confidence interval (0.98 and 0.81, and 0.96 and 0.97). The intraclass 
correlation coefficient method also showed 97% inter-raster reliability.  
Conclusion: Mobile phones as a new system can evaluate the kinematic variables of mandibular disorders with appropriate accuracy and reliability.