IMPACT FORCES DURING HEEL TOE RUNNING

Impact forces have been speculated to be associated with the developme nt of musculoskeletal injuries. However, several findings indicate tha t the concepts of ''impact forces'' and the paradigms of their ''cushi oning'' may not be well understood in relation to the etiology of runn ing injuries and that complex mechanisms may be responsible for injury development during running. The purposes of this paper are (a) to rev iew impact mechanics during locomotion, (b) to review injuries and cha nges of biological tissue due to impact loading, and (c) to synthesize the mechanical and biological findings. In addition, directions for f uture research are discussed. Future research should address the devel opment of noninvasive techniques to assess changes in the morphology a nd biochemistry of bone, cartilage, tendon, and ligaments; researchers should also try to simulate impact loading during activities such as running, focusing on the interaction of the various loading parameters that determine the acceptable windows of loading for biological tissu es.