The design elegance and adaptation to purpose of living organisms have a strong appeal to the mind of an engineer. The examination of the skeletal structure with engineering analysis and experimentation reveals a great sense of fitness for purpose. For it is not only in their form but also in the behaviour of the materials from which they are built up that we find surprises. The mechanical properties of living tissue are quite unmatched by the materials we have available to construct inert engineering artifacts.

Such studies constitute one of the two main preoccupations of what is called "bioengineering", a multi-disciplinary science, involving a diversity of engineers, biologists, orthopaedic surgeons and others. It looks at the beviour of living structures, in particular the human skeletal system, through the eye of the engineer. The other main strand of bioengineering endevour - the application of engineering methods to help restore dieficiencies in function-disablement as a result of trauma, disease processes or congenital defect.

Over the past few decades, in particular, this has seen greatly increased activity and several conspiculous successes. Man-made devices have brought about a transformation in the practise of surgery and many people living pain-free, active lives would otherwise have to cope with serious and progressive disability were it not for the "inert engineering artifacts" which have replaced one or more of their natural structures.