| Popis: |
The terrestrial human walking is an example of adapting design and function to minimize energy expenditure through the pendulum-like mechanism. When humans walk in water environment, two forces are added to the gravitational and ground reaction forces, the buoyancy (or apparent) force and resistive force to the movement. Here, we initially experimentally compare the metabolic cost of walking at different water speeds and depths in order to verify if there is energy optimization in walking in shallow water. The most economic level of immersion is at hip depth (at 0.2 m/s). And, the optimal speed is intermediate, at 0.4 m/s, only at knee immersion depth, and in the remaining deeper depths the optimal speed is as slower as possible. Also, we created a physical model based on the forces acting on shallow water walking, and although the values were larger than the experimental values, the theoretical model was able to explain the optimal depth of shallow water walking in humans. A comparative strategy with data from aquatic animals and human swimming offers us possibilities for analyzing likely behavioral attributes in humans performing aquatic locomotion in shallow water immersion. |
