Geometry and inertia of the human body

Abstract

The aim of this paper is to present geometric and inertial quantities of human body and its impact on movement. The external view of whole body and its parts is represented by the length of the line segments, e.g. during measuring of body height or by comparing of a step length to the length of lower extremities. Curvilinear measurements are used for determining the circumference of body parts. Body planar dimensions are taken into account when air resistance is calculated, while body volume is essential when buoyancy is characterized. Body angles are used for presentation of e.g. body posture. External dimensions can be obtained using anthropometric devices and image processing methods. Internal dimensions for living people can be obtained using such methods as computerized tomography or magnetic resonance imaging. Diagnostic images of the body are used for obtaining tissue data, especially area of surface of tissue image on body intersection. The multiplication by the height of a layer gives the volume of tissues. Inertial quantities are whole body, segment, and tissue mass (absolute and relative), moment of inertia of the whole body and its parts, location of a center of mass in given coordinate system. Values of quantities above are necessary for building the body model for transport analyses and biomedical engineering and also for ergonomic, sport, medicine and other purposes.