Biomechanics or necromechanics? Or how to interpret biomechanical studies.

The field of biomechanics is inextricably linked with orthopaedic surgery: loads and load distribution play a major role in the problems we treat and in the success and failure of many of our treatments. Nonetheless, despite powerful investigational tools, I would argue biomechanics has made a relatively minor impact in clinical practice primarily because most studies fail to account for the major distinction between living and non-living systems: adaptability. While any study requires a clear question or hypothesis or goal, without accounting for adaptability and tissue tolerance, these studies might well be termed "necromechanical." These studies will always have limited clinical relevance unless they contain several key features: 1.) A choice of a mechanical parameter which is arguably a surrogate for relevant biological behavior; 2.) A set of loading regimens which arguably represent the entire range of loadings experienced in vivo; 3.) An explicit discussion of tissue tolerance to the mechanical perturbations of the study; 4.) When appropriate (i.e., the question relates to longer-term effects), an explicit exploration of tissue adaptation over time. Without meeting these requirements, any biomechanical study is suspect and requires interpretation with great caution. When meeting these requirements, biomechanics can provide powerful tools to explain the function of the body and to predict the success or failure of treatments prior to using them on patients.