MATLAB visualization program for analysis of C3D motion capture data of speech and language

Abstract

Investigation of the underlying physiology of speech and language motor control often includes analyses of kinematic parameters derived from fleshpoint tracking. A MATLAB program has been developed to visualize, boundary mark, and analyze aspects of motion capture data in a C3D file format. C3D is the biomechanics data standard for binary 3D data that is widely used in many industries and motion research. Included in the format is marker names, arrays of position data, and analog inputs. While this format is highly versatile, it is difficult to assess the comparison of the markers positions without a visualization program. The developed program allows for flexible comparison of any fleshpoint markers, in any set of repetitions. It also allows for easy visualization of the differences between varying data conditions. Data analysis is done on-the-fly for information such as joint angles through three markers, distance between any two markers, and variability analyses of any selected data. Data are output in a format suitable for additional statistical analyses. Recent analyses using this program were completed on highly complex data streams with over 30 fleshpoint markers. The program provides an incredibly useful tool for exploration of these data and quick analyses of coordination and variability.