The papers presented at the Fourth 'Meeting of the European Society of Biomechanics, held in collaboration with the European Society for Biomaterials in late September 1984 in Davos, Switzerland, are published herewith. The main idea of the meeting was to gather together the many disciplines of researchers and clinicians active and interested in promoting biomechanical knowledge in one interdisciplinary society: the European Society of Biomechanics. We feel that the dialog across the disciplines is one of the important goals of the society, a goal which can be furthered by meetings like the one in Davos. A surgeon, whether a general, trauma or orthopaedic surgeon, is normally brought up without relevant exposure to spe­ cific technical problems. It therefore is not surprising that he speaks a different language with respect to mechanical problems than an engineer. Although a surgeon often has a feeling for what the solution to a particular problem might be, a fruitful inter­ disciplinary collaboration is made difficult by this scientific language barrier. On the other hand, a physicist, chemist, engi­ neer and metallurgist, to name a few, would do well with a realistic perception of the possibilities and limitations of surgery and of the relevance of a solution found to the initial question. Similar problems exist in other areas, e. g. in the field of sports biomechanics in the dialogue betweeen coach and researcher. Interdisciplinary misunderstandings have led to quite some unaeces£ary frustration in the past.