Reliability of three-dimensional motion analysis in assessment of Bell’s palsy

Objective analysis of facial movements forms an important consideration in the assessment and outcomes of several medical disciplines. This study was conducted to investigate the reliability of the threedimensional (3-D) motion analysis system as a method for assessment of Bell’s palsy quantitatively. Sixty female patients suffered from Bell's palsy; their ages ranged from 25-40 years, participated in this study. Three-dimensional motion analysis by Qualisys motion capture system was used to analyze facial movements by measuring specific facial angles. Measurements were taken for both the affected and non-affected sides to measure the facial asymmetry (from both contracted and relaxed positions). The intra-examiner and inter-examiner reliability of the measurement were examined. The measured angles were correlated with the manual muscle testing (MMT) of the corresponding muscles. Facial Disability Index was also used to assess facial function. Statistical analyses revealed that there was a statistical non-significant difference in the angles recorded between both examiners. The intra examiner and interexaminer reliability of the measured angles were highly accurate with Intra-class Correlation Coefficient (ICC) between 0.88 and 0.97. Qualisys motion capture system proved to be strongly correlated with the grades of MMT of the corresponding muscles (Pearson's product moment correlation coefficient [r] ranged from 0.61 to 0.81). It was concluded that 3-D motion analyses by Qualisys motion capture system can be considered as a reliable method for assessment of Bell’s palsy and can detect and characterize a wide range of clinically significant facial functional deficits. [Nevein M.M. Gharib, Sahar M. Adel, Nirmeen A. Kishk, Reliability of three-dimensional motion analysis in assessment of Bell’s palsy] Journal of American Science 2011;7(9):126-134]. (ISSN: 1545-1003). http://www.americanscience.org.