ABSTRACT
Kinetics refers to forces and force systems. This chapter considers how these concepts may be applied with biosystems—particularly human body models. To model the inertia forces, d’Alembert’s principle—a variant of Newton’s second law—is used. In general, there will be two kinds of forces exerted on typical body: those arising externally, so-called applied or active forces; and those arising internally, so-called inertia or passive forces. Applied forces are due to gravity; to be in contact with other bodies, with fabric (e.g., garments), and with structural/component surfaces; and due to muscle/tendon activity. Inertia forces are due to the motion of the typical body in a fixed frame.
