Computer-aided Cephalogram proves beneficial to postural control research

Abstract

　Research on postural sways has been performed for many years and the Cephalogram method is regarded as a conventional technique in this field. As the Cephalogram traces a subject's head movement with a brush pen, operations are usually complicated and its application is limited. This restriction of the recording method of the Cephalogram has lead to its diminishment in recent research. A modern alternative to the conventional Cephalogram is analysis of the center of pressure (COP) by placing a force plate under the foot of a subject. However, in some specific movements, COP cannot represent the movement features of other parts of the body. As a method for directly recording the maintenance process of the body's standing posture by sketching movement trails of the head, the Cephalogram is still a vital method. In order to improve the conventional Cephalogram method, a computer-aided Cephalogram (CAC) based on image analysis is proposed in this paper. To demonstrate and test this CAC method, two experiments are carried out. One is analysis on stance movements: that of leaning forward from the waist and that of leaning forward from the ankle. The other analyses the postural sway in an archer's shooting moments. The results show that the CAC method can result in improvement in precision; moreover, it can discover movement features different from COP analysis. The CAC method is well suited for standing posture movement analysis and is beneficial in studies focusing on the function of the stability of posture.