Centre of Research, Education, Innovation and Intervention in Sport (CIFI2D), Faculty of Sport and Porto Biomechanics Laboratory (LABIOMEP-UP), University of Porto, 4200-450 Porto, Portugal.
Riedel Communications GmbH & Co. KG, R&D Hub Portugal, 4450-718 Porto, Portugal.
Sensors (Basel). 2021 Mar 4;21(5):1783. doi: 10.3390/s21051783.
The surf pop-up is a unique and challenging skill, critical to successful surfing. Hypothesizing that anthropometric characteristics of surfers influence the pop-up performance, we aimed to measure kinematics and ground-reaction forces (GRF) during a simulated pop-up motion, and to relate these variables with anthropometric characteristics. Twenty-three male surfers (age: 28.4 ± 10.1 years old; body mass: 68.3 ± 10.8 kg; height: 1.73 ± 0.07 m; time of practice: 12.4 ± 8.9 years; arm-span: 1.75 ± 8.9 m) perform a simulated pop-up in the laboratory, while GRF and 3D motion-capture data were acquired. The duration of the pop-up was 1.20 ± 0.19 s (60% push-up and 40% reaching/landing phase). During the push-up, the hands were placed 0.46 ± 0.05 m apart and generated a relative total peak-force of 0.99 ± 0.10 N/Weight, with symmetrical impulse of 0.30 ± 0.05 N·s/Weight for the dominant and 0.29 ± 0.07 N·s/Weight for the nondominant hand. Elbow angles were not different during the peak force application (110 ± 18° vs. 112 ± 18°, respectively) of the push-up phase. During the landing phase, the feet were placed 0.63 ± 0.10 m apart and generated a relative peak force of 1.63 ± 0.18 N/Weight. The impact force during landing was applied unevenly between the rear foot (28%) and the front foot (72%). In conclusion, most anthropometric-related variables showed no relationship with performance variables, with the exception of an inverse relationship between muscle mass and pop-up total duration. We also observed no differences in upper- and lower-body kinematics between the dominant vs. nondominant hands and among surfers who preferred a regular vs. "goofy-foot" stance. Finally, the force profiles between hands were similar and symmetric, while the lower extremities during the reaching phase were different, with the front foot applying greater force than that of the rear foot.
冲浪弹跃是一项独特且具有挑战性的技能，是成功冲浪的关键。我们推测冲浪者的人体测量特征会影响弹跃表现，因此旨在测量模拟弹跃动作过程中的运动学和地面反作用力（GRF），并将这些变量与人体测量特征联系起来。23 名男性冲浪者（年龄：28.4±10.1 岁；体重：68.3±10.8 千克；身高：1.73±0.07 米；练习时间：12.4±8.9 年；臂展：1.75±8.9 米）在实验室中进行模拟弹跃，同时采集 GRF 和 3D 运动捕捉数据。弹跃持续时间为 1.20±0.19 秒（60%推起和 40%伸展/着陆阶段）。在推起阶段，双手之间的距离为 0.46±0.05 米，产生的相对总峰值力为 0.99±0.10 N/体重，主导手的对称冲量为 0.30±0.05 N·s/体重，非主导手的对称冲量为 0.29±0.07 N·s/体重。在推起阶段的峰值力应用期间（分别为 110±18°和 112±18°），肘部角度没有差异。在着陆阶段，双脚之间的距离为 0.63±0.10 米，产生的相对峰值力为 1.63±0.18 N/体重。着陆时的撞击力不均匀地分布在后脚（28%）和前脚（72%）之间。总之，大多数与人体测量相关的变量与表现变量没有关系，除了肌肉质量与弹跃总持续时间之间存在反比关系。我们还观察到，在惯用手和非惯用手之间，以及在更喜欢常规站位和“反脚站位”的冲浪者之间，上下半身的运动学没有差异。最后，双手之间的力曲线相似且对称，而在伸展阶段，下肢不同，前脚施加的力大于后脚。
