Kinematic changes during running-induced fatigue and relations with core endurance in novice runners

Objectives: This study aimed to investigate kinematic changes experienced during running-induced fatigue. Further, the study examined relations between kinematic changes and core endurance. Design: Repeated measures and correlation. Methods: Seventeen novice runners participated in a running-induced fatigue protocol and underwent core endurance assessment. Participants ran at a steady state corresponding to an intensity of 13 on the Borg scale and continued until 2 min after a Borg score of 17 or 90% of maximum heart rate was reached. Kinematic data were analyzed for the lower extremities and trunk throughout a running protocol and, on separate days, core endurance measures were recorded. Changes in pre- and post-fatigue running kinematics and their relations with core endurance measures were analyzed. Results: Analysis of peak joint angles revealed significant increases in trunk flexion (4 degrees), decreases in trunk extension (3 degrees), and increases in non-dominant ankle eversion (1.6 degrees) as a result of running-induced fatigue. Post-fatigue increased trunk flexion changes displayed a strong to moderate positive relation with trunk extensor core endurance measures, in contrast to expected negative relations. Conclusions: Novice runners displayed an overall increase in trunk inclination and increased ankle eversion peak angles when fatigued utilizing a running-induced fatigue protocol. As most pronounced changes were found for the trunk, trunk kinematics appear to be significantly affected during fatigued running and should not be overlooked. Core endurance measures displayed unexpected relations with running kinematics and require further investigation to determine the significance of these relations. (C) 2013 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.