Kick Study in Swimming Using Computational Fluid Dynamics

Background and Objectives: For individuals with limb absence, staying active through sports can provide both social and physical benefits, with many turning to swimming. To prevent muscle imbalances and injuries, it is crucial to have a prosthetic that matches the propulsion of the intact limb, reducing strain on the intact limb. This study analyzes different foot movements in the crawl stroke kick to determine the most efficient model for swimming. Methods: This study is carried out through COMSOL 6.2 using Computational Fluid Dynamics to calculate the distance each model travels in one second. A sine wave is developed to define the foot rotation and the calf movement. Different phase differences of the foot movement relative to the original model are also tested. Results: The distance between each amplitude of the foot movement increases as the amplitude gets larger. For example, the difference in distance traveled between amplitudes of 0.4 and 0.5 radians is 0.84 cm, compared to 0.489 cm between 0.1 and 0.2 radians. A phase difference of 7π/4 produced the greatest distance traveled within one second. This analysis determines how close the original ankle technique in the crawl stroke is to the most efficient and powerful way of swimming. Conclusions: Within this simplified model, a prosthetic foot with a flexible ankle produced greater hydrodynamic propulsion than a fixed foot. These findings suggest that an ankle designed to more closely match the motion of the sound limb may be a favorable feature for sport-specific swimming prosthetics, offering a plausible strategy, grounded in the broader musculoskeletal literature, for reducing the risk of overstraining injuries associated with movement asymmetry.