보행분석시스템을 이용한 관절 운동 계산 방법

Abstract

Joint motion is a fundamental measurement to understand the function of joints. There are a number of commercial motion capture systems that contain multiple cameras, a wand, and software. End users can follow the product manual to put markers on a patient, record marker trajectories, perform labeling and calculate temporal joint angles. There are also researchers who are interested in measuring temporal three-dimensional distances or angles. Understanding the fundamentals of the motion capture hardware and kinematics analysis software would help finding many interesting clinical applications for clinical researchers. Hardware of a motion capture system consists of multiple cameras, reflective markers, and a calibration wand. Software of a motion capture system provide functions for recording, marker labeling, and kinematic analysis (joint angle calculation). Basically the cameras see markers and calculates three-dimensional positions of them in the laboratory space (or laboratory coordinate system). With the raw marker trajectories temporal length changes between two markers or temporal pose changes of a rigid body with respect to the laboratory coordinate system can be calculated. Kinematics usually mean a movement of a rigid body relative to another body which is connected by a joint which usually a rotational joint in human body. Inverse kinematics calculates angle of the joint from the marker positions on two bodies around the joint. Alternatively, joint kinematics can be visualized and quantified as arthrokinematics. All these aspects of joint motion analysis will be briefly explained in the lecture. The preparation of this lecture was financially supported by Project for Research and Development of Police Science and Technology (PA-C000001) and by the Basic Science Research Program (NRF-2017R1A2B2010763) funded by the Ministry of Science and ICT.