Analysis of the sitting posture comfort based on motion capture system and JACK software

Abstract

With the development of science and technology, people have higher demand for comfortable seats. However, comfort is a complicated concept to apply in evaluating a sitting chair. There is no established assessment method which could evaluate the sitting chair comfort at present. Most of the current evaluation methods are based on single analysis, and lack multi-analysis of the problem. This paper proposes a new method which integrates investigation methods in real environment and virtual environment. Firstly, Motion Analysis Eagle Digital System is used to capture the body motion of participants, and obtain the human body each joint point in the space. Using a selfdeveloped MATLAB program to analyze the distinct differences on the joint angle and the torques when seated in an Ergokinetic™ Seat chair and seated in a standard office chair. Then, based on the exact data recorded by optical motion capture systems and data processing by JACK software, put the track data files to JACK software, then use TAT report tools to output data and analyze the relative motions data by MATLAB software. Using self-developed MATLAB programs to calculate joint angles, torques and muscle force. Meanwhile, study the muscle comfort index to explore new method to evaluate sitting posture comfort index. The sitting posture comfort index method combined with human body digital model can analyze the siting posture comfort. Also, this research could be applied on optimize comfort level of the body sitting posture.