STANDARD ERROR OF THE CENTER OF MASS (CM) POSITION IN A THREE DIMENSIONAL SPACE OBTAINED THROUGH KINECT™

Resumo

Analysis, diagnosis and intervention methods in the biomechanics approach of the human movement have shown to be a field in need of new tools concerning health sciences, sports, quality of life and related areas. Therefore, this very study has the objective of verifying standard error of the Centers of Mass (CM) on human body segments through Microsoft™ Kinect™. Methods: a single subject, height 1.87m, wingspan 1.75m, and body mass 101.10kg, was placed 3.60m far from Kinect’s™ lens. For data collecting, the subject was instructed to walk towards the forementioned hardware in a straight line until reaching the marked distance of 1.80 from it, and then return to the starting position, repeating this movement thrice. Data acquisition rate was set at 30Hz, and 14 body segments CM positions were captured on X, Y and Z axes related to the global referential. Data were filtered by FFT, 7Hz cut-off. Standard error was calculated in all of the three situations. Results: the standard error calculated for the 14 body segments CM matched an equivalent of 1.0x10-4m (meaning tenths of millimeters). Those results corroborate other tests already run, such as accuracy, precision and RMS error tests, consolidating Kinect™ potentiality as an analysis, diagnosis and intervention instrument for health sciences, sports, medicine, logistics, marketing, human movement, among other fields.