Biomechanics has always been a major factor in the study of orthopedic surgery. Understanding the mechanics of the function and failure of musculoskeletal tissues is essential to determining how to protect, heal, and improve those tissues. To know the range of forces on different tissues involved in various activities is to be able to know how strong to make implants or braces. While determining those forces is not an exact science, it is a necessary part of orthopedic science.
For several reasons, most orthopedic biomechanics studies utilize cadaver tissue. It is easy to obtain and behaves similarly to normal tissue. The processing of cadaver tissue does make it somewhat stiffer than normal tissue and cadaver tissue is typically from the elderly, so those factors must be considered.
While every facet of orthopedic surgery is currently under scrutiny concerning biomechanics of failure and treatment of failure, certain areas are of more urgent examination. Osteoporosis is a major problem around the world and is getting worse as we are becoming more sedentary, living longer, and getting less calcium and vitamin D to strengthen our bones. Biomechanics plays a critical role to understand how bone weakens as bone density decreases. When bone-building drugs are given, we need to understand how the bone properties change regarding stiffness, elasticity, and whether weak points are created. In terms of soft musculoskeletal tissues, aging leads to increased stiffness and decreased ability to tolerate sudden loads—altered viscoelasticity.