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Running on a slope: A collision-based analysis to assess the optimal slope
1Laboratory of Biomechanics and Physiology of Locomotion, Institute of NeuroScience, Université catholique de Louvain, Louvain-la-Neuve, Belgium.
Journal of Biomechanics
|January 7, 2019
Summary
Running energy loss is minimized at a ~-6° slope, where the body's center of mass (COM) collision becomes pseudo-elastic. This optimal slope reduces metabolic energy consumption during running.
Area of Science:
- Biomechanics
- Human Locomotion
- Energy Metabolism
Background:
- Running involves energy dissipation during the stance phase to redirect the body's center of mass (COM) vertically.
- Understanding how slope and speed affect these energy losses is crucial for optimizing running economy.
Purpose of the Study:
- To analyze changes in running energy loss with varying slope and speed using a collision-based approach.
- To investigate the collision angles during the absorptive and generative phases of stance.
Main Methods:
- Evaluated the average collision angle (deviation from perpendicular force-velocity vectors) during stance.
- Analyzed collision dynamics across different slopes (uphill, level, downhill) and speeds.
- Quantified changes in the absorptive and generative phases of the running stance.
Main Results:
- On level ground, the generative phase collision angle exceeded the absorptive phase angle.
- Uphill running increased the generative nature of collisions.
- Downhill running at constant speed saw decreased generative and increased absorptive phase angles.
- A slope of approximately -6° resulted in a 'pseudo-elastic' collision, minimizing energy loss.
- Metabolic energy consumption was lowest at this optimal negative slope.
- Steeper downhill slopes led to absorptive collisions.
Conclusions:
- Running biomechanics and energy expenditure are significantly influenced by slope.
- A specific negative slope (~-6°) optimizes running by minimizing collisional energy losses, leading to reduced metabolic cost.
- Increasing speed generally enhances the generative nature of collisions across all slopes.
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