The assessment of fatigue-related changes in stride mechanics, variability and long-range correlations in recreational and elite distance runners using foot-mounted inertial sensors

Date
2017-03
Authors
Brahms, Clemens Markus
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Faculty of Graduate Studies and Research, University of Regina
Abstract

This thesis was designed to assess stride mechanics, variability and long-range correlations during running, as well as their relationship with fatigue and skill level. For this purpose, three separate experiments were conducted. As a first step, it was established whether a simple hardware setup consisting of a wireless foot-mounted inertial measurement unit (IMU) was capable of accurately measuring individual stride length vectors during distance running. The results showed that the sensor-based method displayed excellent levels of agreement with a 3D motion capture system as the criterion. Subsequently, the same setup was used to track a set of gait variables in a group of elite and recreational runners during an exhaustive overground run. It was established that long-range correlations (LRCs) decreased over the run, while no significant changes were observed in the coefficients of variation (CV). Group differences were found in mean stride length, contact time and peak impact acceleration, stride time CV as well as peak impact acceleration FSI. A final study assessed the impact of a fatiguing drop jump protocol on joint stiffness, stride mechanics and measures of variability. As before, a group of elite and recreational distance runners were recruited for this experiment. It was found that joint stiffness was significantly reduced after the fatiguing jumps. Additionally, mean stride time, as well as LRCs in the stride time and stride length series were reduced in response to the jumps. Group differences existed in knee joint stiffness and mean stride length. Notable interaction effects indicated that elite and recreational runners reacted differently to the fatiguing jumps with respect to mean ankle joint stiffness and stride length. Together, this thesis demonstrates that long-range correlations serve as a potential marker of neuromuscular fatigue during prolonged running. It also confirms that IMUs are capable of tracking a variety of gait parameters across a range of different distance running speeds. Keywords: distance running, fatigue, stride variability, inertial sensors, IMU

Description
A Thesis Submitted to the Faculty of Graduate Studies and Research In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in Kinesiology and Health Studies, University of Regina. xiv, 190 p.
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