Forces in Joints

Abstract

The skeleton is first and foremost a mechanical organ. Its primary functions are to transmit forces from one part of the body to another and to protect certain other organs (e.g., the brain) from mechanical forces that could damage them. Therefore, the principal biologic role of skeletal tissues is to bear loads with limited amounts of deformation. To appreciate the mechanical attributes that these tissues must have to perform this role, it is necessary to learn something about the forces which whole bones normally carry. In most cases, these forces result from loads being passed from the part of the body in contact with a more or less rigid environmental surface (e.g., the heel on the ground when walking) through one or more bones to the applied or supported load (e.g., the torso). In addition to the forces transmitted in bone-to-bone contact, muscle and ligament forces act on the bones, and these forces (especially the muscle forces) are large and important.

...mechanical science is of all the noblest and most useful, seeing that by means of this all animate bodies which have movement perform all their actions...

Leonardo Da Vinci (1452–1519)