INTRODUCTION

The study of the biomechanics of sport is one field in which finding the most efficient way of performing a movement is crucial to the success of the participants. For instance, running more efficiently, or more economically in terms of energy expenditure, is mostly accomplished with changes in training which may or may not affect biomechanical aspects such as stride length and frequency (Anderson, 1996). However, attempts at adjusting the efficiency of a runner's stride are often met with resistance possibly due to individual body types and morphologies such as percent body fat, pelvic width and leg length (Morgan et al, 1989 and Anderson, 1996). Of note is that many of the biomechanical factors which positively correlate to running economy are present more often in males than in females (Anderson, 1996).

We are attempting to establish a stronger connection between the hip angle and running economy by examining the crossover of two runners with different hip angles. Since the foot must strike fairly close to directly under the center of mass of the runner in order to support him properly, it seems that a runner with a larger hip angle will have a greater amount of displacement from a direct line of motion in the sagittal plane of the hip joint to effectively support his body. Termed the "base of gait," this phenomenon is called crossover when it is negative, or crosses the midline of the body (Cavanagh, 1987). A runner who has a large crossover would actually be covering a greater absolute distance than a runner whose body needs little or no crossover for support. Since running economy has been standardized as a measurement of oxygen cost per kilogram of body mass per kilometer run (Anderson, 1996), this value will be different if we consider the actual distance covered as opposed to the straight line distance usually measured in assessments of running economy.