| Autor: |
Burns GT; School of Kinesiology, University of Michigan, Ann Arbor, MI, USA.; United States Olympic and Paralympic Committee, Colorado Springs, CO, USA., Tam N; Sport Science Laboratory, On AG, Zurich, Switzerland., Langerak NG; Neuroscience Institute and Division of Neurosurgery, University of Cape Town, Rondebosch, South Africa.; Department of Research, Sint Maartenskliniek, Nijmegen, the Netherlands.; Department of Medical BioSciences, Radboud University Medical Center, Nijmegen, the Netherlands., Zernicke RF; School of Kinesiology, University of Michigan, Ann Arbor, MI, USA.; Department of Orthopedic Surgery, University of Michigan, Ann Arbor, MI, USA.; Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA., Lamberts RP; Division of Movement Science and Exercise Therapy (MSET), Department of Exercise, Sport and Lifestyle Medicine, Faculty of Medicine and Health Sciences, Stellenbosch University, Stellenbosch, South Africa. |
| Abstrakt: |
Ultramarathons are a unique model to study the effects of systemic fatigue in athletes. This investigation applied the spring-mass template to study runners before and 2 days after a road ultramarathon to characterize the effects of fatigue on systemic gait patterns. Overground kinetics were captured 7 days before and 2 days after the event in 14 runners. Traditional kinetic and spring-mass parameters were calculated, along with nonlinear regression-derived parameters and spring-mass model fit metrics. After the ultramarathon, vertical force magnitudes and loading rates were unchanged, but impact peaks increased (1.88 ± 0.08-1.95 ± 0.10 bodyweight). Ground contact times were modestly shorter (-3 ± 1 ms), resulting in increased leg stiffness (10.0 ± 0.5-10.3 ± 0.5 kN/m) with equivocal vertical stiffnesses. The deviation from the modeled spring-mass kinetics also increased (171.3 ± 15.0-181.4 ± 16.5 N). Overall, the systemic mechanical behaviors of the runners persisted despite the fatigue and stress induced by a road ultramarathon. These findings support previous observations that runners maintain gross mechanical behavior when fatigued with small compensatory changes in spatiotemporal and traditional spring-mass characteristics. However, these findings also suggest that the variability within that gross behavior may increase after stress, suggesting new opportunities for quantifying those deviations. |
