IMU-based determination of fatigue during long sprint

Stride parameters represent basic and useful information on track and field sprint performance. Contact mats or opto-electronic systems allow precise and unobtrusive measurements of those parameters, but their use is limited in space. Hence, there is a lack of research regarding the changes of temporal parameters throughout the competition distance (especially for long sprint), e.g. as a result of fatigue. Wearables, respectively inertial measurement units (IMUs), are not bound to limitations in space and therefore offer challenging opportunities for in-field diagnosis. This paper presents a wearable device for detecting and monitoring stance durations and step frequencies during sprinting. An application in (repetitive) long sprints is presented that analyzes changes of the temporal structure of performance parameters as a result of fatigue and level of expertise. Results indicate that the device provides reliable and accurate measurements of temporal parameters during sprinting and offers a deeper insight to movement characteristics of long sprint.