Mechanisms of shock attenuation via the lower extremity during running.

Due to the increase in popularity of running or jogging as a pastime there has been an associated increase in injuries. Evidence of a causative link between excessive shock during running and these injuries has prompted a great deal of research interest centred around the reduction of the shock. This paper outlines the various ways in which shock is both produced and attenuated by the body. These include both active (proprioception, joint position, muscle tone) and passive (elasticity of bone, cartilage, synovial fluid and soft tissues) mechanisms and both are affected by the style of running. Artificial shock attenuation via footwear and/or insoles is discussed and the balance between shock attenuation and rearfoot control mentioned. It is found that as shock attenuation capacity increases, rearfoot control decreases, and this causes other injuries due to the lack of control. Therefore a balance has to be found between the two and this is suggested as an area for further research. The design of running shoes is examined and the sole shape and material is discussed with regard to improving running performance and reduction of injury.