Factors determining biomechanical characteristics of the swimming start, their contribution to starting enhancement and its performance prediction

Abstract

The thesis complements current knowledge about ventral swimming start, its structure as well as factors determining its performance and optimization. Five experimental studies were conducted to expose key factors affecting the biomechanical characteristics of the swimming start. Two of them focused on consequences brought by different starting positions, one explores back plate placement effect on the temporal structure of swimming start, next compared ventral start performed by males and females, and last searched for the link between starting performance and lower body motor abilities measured with the countermovement jump (CMJ). During pool tests, all participants completed ventral starts which were monitored from starting signal up to the 15-m mark. To collect spatiotemporal data describing swimming starts the video cameras, Qualisys Motion Capture system, and 3D dynamometric starting block were used. During the CMJ test, force platforms were employed to collect signals of ground reaction forces. Acquired data were analyzed using dedicated software. Analyses conducted in the thesis revealed that: (i) for national-level athletes, the kick-start forward demonstrates superiority at start time measured at 5-m and 15-m over kick-start backward, followed by handle-start and grab-start; (ii) the kick-start forward provides a temporal advantage over its backward variant in a group of international level female junior swimmers; (iii) back plate position has a significant effect on lower limb temporal movement characteristics measured as duration of rear foot take-off and front foot stand; (iv) male swimmers, by spending less time in the block phase, swimming faster while in the water, reaching higher take-off velocity and longer flight distance, take a starting advantage over their female counterparts; (v) depending on the starting features, a different strategy regarding movement structure and their contribution has to be addressed with reference to overall start performance enhancement; (vi) the CMJ test results correlate with the overall kick-start performance, as well as variables of the start that particularly rely on the movements performed by the lower limbs. By examining the link between various individual contributing parameters, the predicting variables constituting key factors in starting performance assessment and its future development were disclosed. This way, the priority areas and recommendations for wider assessment and monitoring were exposed, which should serve for more comprehensive approaches in swimming start enhancement.