Effects of fatigue on center-of-mass acceleration during a prolonged overground run

Objective: The aim of this study was to assess for fatigue related changes in center-of-mass (COM) acceleration during a prolonged overground run in a group of healthy male runners using a tri-axial accelerometer attached to a runner’s low back. Methods: Thirty healthy male runners’ performed an eight kilometer (20 laps) overground time trial paced run on a 400 meter athletics track. Kinematic measures assessed regularly throughout the run included signal energy and acceleration impulse in the anteroposterior (AP), mediolateral (ML) and vertical (VT) directions, contact time (CT) and step frequency. A repeated measures analysis of variance comparing each data collection point to the initial was used to identify fatigue related changes. Results: Compared to initial measurement, CT significantly increased during laps six to 18 in addition to significant increases in ML signal energy and decreases in AP impulse identified from lap four to 20. Conclusion: A tri-axial accelerometer was able to identify changes in ML and AP COM acceleration measures plus a runner’s CT indicating fatigue was impacting a runner throughout a prolonged run. Limited changes in VT acceleration measures were identified suggesting biomechanical fatigue related running changes predominately occur in the horizontal plane. Future research investigating the effects of fatigue on running should use frequent and regular data collection to identify fatigue related running changes