Comparison of Different Type Start Techniques in Bi-Finswimming

Objective: This study aimed to experimentally investigate the biomechanical and performance differences between the Grab Start (GS) and the Kick Start (KS) with each leg on the kickplate (KSR, KSL) in Bi-Finswimming (BFS). It focused on the effect of foot placement on the OSB11 starting block to determine potential performance advantages and contribute evidence-based recommendations for optimizing start techniques in competitive BFS. Methods: Thirteen national-level finswimmers (7 males, 6 females; age: 17.7 ± 2.1 years) voluntarily participated. Each athlete performed two trials of three start techniques (GS, KSR, KSL) over three days in randomized order. Four synchronized cameras recorded video data. Performance metrics (time to 5 m, 15 m, 25 m, reaction time, block time (BT), flight time (FT), and entry characteristics) along with joint angles (hip, knee, ankle), were analyzed using Kinovea software. Results: No significant gender differences were found (p > 0.05). Significant differences emerged between the starting techniques, with KS showing faster times (p < 0.001). BT was significantly longer in GS compared to KS (p < 0.001), while FT was shorter in GS (p = 0.002). Faster T5, T15, and T25 were associated with increased flight distance and longer FT in KSL. Conclusions: The findings suggest that the Kick Start technique generally outperforms the Grab Start, especially in block time, in Bi-Finswimming. It is recommended that this technique be legalized by CMAS for competition use.