It is widely recognized that numerical analysis is a useful ta al common ta the fields of engineering, applied mathematics and mechanics, and medical science. Computer simulation and modeling have contributed much ta the understanding of a wide variety of biomedical phenomena. In particular the use of numerical techniques is essential for solving problems involving extremely complex geom- etry and physical properties that arise in a wide range of biomechanics. The increased speed and expanded storage capacity of modern computers, together with newly advanced numerical and programming techniques, have greatly im- proved the potential for studying complicated biomedical processes. Computer modeling techniques and their applications in the field of biome- chanics have shown remarkable development in J apan in the past few years. This book focuses an these advances and shows how computer modeling and simula- tion are being utilized ta aid and assist researchers, scientists, and clinicians in their understanding of biomedical systems from the biomechanical point of view. The papers included in this book falI within three main areas of interest: orthopedic, orthodontic, and skeletal mechanics; circulatory mechanics; and bio- logical and living systems. This book contains highly original papers that have been carefulIy selected from the studies financialIy supported by a 3-year Grant- in-Aid for Scientific Research an Priority Areas (Biomechanics, Nas.