A Kinematics Comparison of Different Swimming Relay Start Techniques

Abstract

In swimming relay races, various start techniques are performed by swimmers, but it remains unclear which technique leads to a better start performance. Therefore, the purpose of the present study was to compare the kinematic characteristics of different relay start techniques with the new starting block Omega OSB11. Eleven international youth swimmers were filmed during 1) no step with parallel feet, 2) no step with separated feet and 3) one-step starts and their centre of mass kinematics calculated with 2D-DLT algorithms. Results indicate that differences between techniques were detected in the spatiotemporal parameters of the block and aerial start phases (e.g., initial and take-off positions, entry height, preparation and changeover times) and in selected parameters of the underwater phase (e.g., emersion time and distance, underwater time and distance). However, no statistical effects were found in 5 m, 10 m and 15 m start times, nor in horizontal take-off velocity, despite an observed trend for the one-step start to be superior to the non-step techniques. These results suggest that differences between relay techniques could rely more on the swimmer's body posture (angular kinematics) on the block, flight and underwater phases than on the centre of mass linear kinematics.

Kinematic Analysis of the Underwater Undulatory Swimming Cycle: A Systematic and Synthetic Review

“…However, from then on, 13 out of 19 research studies employed at least 100 Hz, with 100-120 Hz being the most common selection. This is in line with frame rates reported in research about swimming starts [50] or turns [51].…”

“…Filtering procedures for the continuous raw data of UUS typically consisted of a low-pass Butterworth filter with cut-off frequencies that ranged from 4 to 7 Hz, with 6 Hz being the most common frequency. These cut-off frequencies are usually employed in swimming motion [52], although they are lower than those employed for the swimming starts [50]. The calculation of real space coordinates from the screen (digitised) coordinates was performed by either mean of linear scaling techniques or DLT algorithms [30] in 16 out of 25 studies.…”

“…Gonjo and Olstad [29] reported 20% faster velocity in the first underwater kicking after the starting dive than the wall push-off. This could be explained by velocity differences when diving off the starting block [50] compared to pushing off the wall [46]. In addition, the swimmer's body position was closer to horizontal when kicking after pushing off the wall, and this could be coupled with other segmental differences.…”

Effects of Extended Underwater Sections on the Physiological and Biomechanical Parameters of Competitive Swimmers

“…Regardless of the experimental condition, distances traveled underwater from a dive start (lap 1) were 3-3.5 m longer than when pushing off the turning wall (laps 2 and 3). This represents a greater difference than the typical flight distances observed in elite youth swimmers during dive starts (Qiu et al, 2021), but differences were confirmed by the greater number of underwater kicks observed in lap 1 vs. laps 2 and 3 (Figure 3).…”

Application of Computer Vision and Deep Learning in Swimming Action Recognition and Evaluation

“…In order to adapt to the interaction between multiple endpoints and the migration of future cloud services, a network structure of an underwater swimming posture intelligent detection model was adopted [13][14]. This model constructs a unified support service layer that can achieve unified support services for desktop, mobile, and future web pages.…”