Biomechanics is a subfield of mechanics concerned with the study of mechanical forces acting at any of the hierarchical levels within or upon living organisms (or possibly groups thereof), though it blends over into thermodynamics at the molecular level, where static and dynamic descriptions of the action of forces meet. Direct effects on the environment due to such movements (e.g. the movement of water due to a fish swimming in it) also fall into the scope of this discipline, as do processes like gliding or floating organisms, or flow within or along organisms.
The more static examples include the balance -- also known as tensegrity -- of tension and compression of skeletons, be they cytoskeletons, endo- or exoskeletons. Dynamic examples include the movements (active or passive) of