Biomechanics (from Ancient Greek: βίος "life" and μηχανική "mechanics") is the application of mechanical principles to biological systems, such as humans, animals, plants, organs, and cells. Perhaps one of the best definitions was provided by Herbert Hatze in 1974: "Biomechanics is the study of the structure and function of biological systems by means of the methods of mechanics". The word biomechanics developed during the early 1970s, describing the application of engineering mechanics to biological and medical systems. In Modern Greek, the corresponding term is εμβιομηχανική.
Biomechanics is closely related to engineering, because it often uses traditional engineering sciences to analyse biological systems. Some simple applications of Newtonian mechanics and/or materials sciences can supply correct approximations to the mechanics of many biological systems. Applied mechanics, most notably mechanical engineering disciplines such as continuum mechanics, mechanism analysis, structural analysis, kinematics and dynamics play prominent roles in the study of biomechanics.
Usually biological system are more complex than man-built systems. Numerical methods are hence applied in almost every biomechanical study. Research is done in a iterative process of hypothesis and verification, including several steps of modeling, computer simulation and experimental measurements.