A Complex Semi-automatic Method for Kinetic and Two-dimensional Kinematic Motion Analysis for Posture and Movement Investigation

Abstract

Functional reach (FR) – maximal forward reach with both arms while standing, is a well-known dynamic balance test. Different underexplained reaching strategies exist. This study was motivated by the need of an affordable and robust approach for their evaluation. We introduce a complex semi-automatic method for two-dimensional kinematic and kinetic analysis based on video capture with inexpensive camera, free automatic marker tracking software, pedobarographic measurements and problem-oriented algorithms for kinetic and kinematic data evaluation. Subjects performed FR with passive markers on their right side while standing on a Tekscan platform. Kinematic and kinetic data were simultaneously collected. Video trimming by sound was applied for synchronization between video and platform recordings. Automatic object tracking by color (Viana.Net) was applied for kinematic measurements. Center-of-pressure excursions were evaluated by Tekscan software. All data were further processed by problem-oriented algorithms (MatLab). Evaluated measures: FR length, horizontal and vertical marker paths, ankle and hip angles and their corresponding linear or angular velocities while moving forward or backward. During these movements the horizontal displacements of the center-of-gravity marker highly correlated with center-of-pressure anterior-posterior sway. The method allows measuring distances, angles and velocities. It is prospective for concerted kinetic and two-dimensional kinematic analysis of dynamic standing balance.

Keywords

• Functional reach
• Posture
• Motion analysis
• Center-of-pressure.