Biomechanical Testing: Key concepts for medical device design include biomechanics, biocompatibility, and biofunctionality Design of a medical device requires extensive testing. Biomechanics is the field that establishes the mechanical properties of biological tissues such as bones, tendons, ligaments, and muscles. This requires investigation and testing of biological tissues under various loading conditions. Biomechanics applies engineering principles to biological systems and it also requires careful analysis of the biological tissue.