Affect of swimming depth on spatiotemporal kinematics of lower-limb breaststroke actions in national-level male swimmers: A discrete variable and time-series evaluation

Swimming depth considerably influences intersegmental coordination in breaststroke; nevertheless, its particular influence on spatiotemporal group of the lower-limb motion stays unclear. This examine investigated kinematic modifications of the breaststroke kick throughout maximal versus submaximal intensities utilizing a twin strategy of discrete variables and time-series analyses. Nine aggressive male swimmers carried out 25-m breaststroke trials at each intensities whereas three-dimensional kinematics had been captured utilizing a multi-camera movement evaluation system. The kick cycle was divided into “leg sweep”, “leg lift and glide”, and “leg recovery” phases. Data had been analyzed utilizing paired t-tests for discrete metrics and Statistical Parametric Mapping (SPM) for time-series trajectories, with normalization utilized to each the full kick cycle and particular person part durations. Submaximal swimming was characterised by considerably longer absolute and relative durations of non-propulsive phases, particularly the “leg lift and glide” part (59.09 ± 5.72% vs. 34.45 ± 12.11% in maximal, p < 0.001), leading to a 50.3% higher horizontal centre of mass displacement per kick (2.24 ± 0.38 m vs. 1.49 ± 0.30 m in maximal, p < 0.001) regardless of decrease swimming velocity. Conversely, maximal swimming elicited compressed part timing, earlier prevalence of peak joint occasions and better angular velocities, notably close to part transitions, and higher vertical centre of mass displacement. Notably, joint ranges of movement and section widths remained constant throughout intensities, indicating a preservation of the spatial motion patterns. These findings display that lower-limb motion variations to swimming depth in breaststroke are predominantly pushed by temporal reorganization and phase-coordination shifts fairly than spatial modification of the joint trajectories.