THE EFFECT OF SPEED ON LOWER EXTREMITY JOINT STIFFNESS DURING GRADED RUNNING

Abstract

Joint stiffness is defined as a given joint’s resistance to angular displacement under mechanical loading expressed as a moment of force.1 Increased joint stiffness is associated with the inability to adequately attenuate shock throughout the body, which is a mechanism associated with an increased risk of running related injuries.2 Understanding the factors that influence stiffness has potential application in injury prevention and rehabilitation with respect to running related overuse injuries.3 Across the literature, increases in running speed have been correlated with increased joint stiffness.4 However, this relationship has only been examined during level ground running; the effect of speed on joint stiffness during uphill and downhill running is relatively unexplored.1 The purpose of this study is to examine the effect of speed on joint stiffness and quantify differences in stiffness between the hip, knee, and ankle, and examine the relationship between foot strike patterns and joint stiffness during graded running.