See biomechanics in American Heritage Dictionary 4
(bīˌō-mĭ-kănˈĭks)
noun
(used with a sing. verb) The study of the mechanics of a living body, especially of the forces exerted by muscles and gravity on the skeletal structure.
(used with a pl. verb) The mechanics of a part or function of a living body, such as of the heart or of locomotion.