Alhammoud Marine, Hansen Clint, Meyer Frederic, Hautier Christophe, Morel Baptiste
French Ski Federation, Annecy, France.
Inter-University Laboratory of Human Movement Biology (EA 7424), University Claude Bernard Lyon 1, Lyon, France.
Front Sports Act Living. 2020 May 15;2:56. doi: 10.3389/fspor.2020.00056. eCollection 2020.
This study used wireless technology to investigate joint kinematic characteristics of the four alpine skiing disciplines. Knee and hip angles were measured in 20 national team alpine skiers during 253 ski runs under FIS regulation, including: 85 Slalom (SL), 123 Giant Slalom (GS), 29 Super Giant Slalom (SG), and 16 Downhill (DH). Data were analyzed by outside (OL, = 2,087) and inside leg (IL, = 2,015). The proportion of concentric and eccentric phases as well as the proportion of the quasi-isometric phase defined between ±20°.s depended on the discipline in interaction with the IL/OL ( < 0.001). The results showed a lower knee quasi-isometric duration on OL in SL (11%) than other disciplines (DH: 38%; SG: 42%; GS: 34%, < 0.001, > 1.8), suggesting a highly dynamic style. Quasi-isometric mode was significantly longer on OL than IL in GS (34 vs. 20%, < 0.001, = 1.16) and SG (42 vs. 28%, < 0.001, = 1.11) but was significantly longer on IL than OL in SL (19 vs. 11%, < 0.001, = 0.64). Thus, GS and SG showed similarities, with a significantly faster knee eccentric mean angular velocity on IL compared to OL (GS -58 vs. -54°.s, SG -52 vs. -45°.s, < 0.001, ≥ 0.22) whereas SL showed an opposite pattern (-72 vs. -89°.s, < 0.001, = 1.10). The quasi-isometric phase was overlooked in previous studies but is crucial to consider. The current data may be used to train the outside and inside leg specificities incorporating discipline-specific contraction modes and exercises.
本研究采用无线技术来调查高山滑雪四个项目的关节运动学特征。在国际滑雪联合会（FIS）规则下，对20名国家高山滑雪队运动员在253次滑雪滑行过程中的膝关节和髋关节角度进行了测量，包括：85次回转（SL）、123次大回转（GS）、29次超级大回转（SG）和16次速降（DH）。数据按外侧腿（OL，n = 2087）和内侧腿（IL，n = 2015）进行分析。向心和离心阶段的比例以及在±20°·s之间定义的准等长阶段的比例取决于项目与内侧腿/外侧腿的相互作用（P < 0.001）。结果显示，回转项目中外侧腿的膝关节准等长时间（11%）低于其他项目（速降：38%；超级大回转：42%；大回转：34%，P < 0.001，ES > 1.8），表明其风格高度动态。在大回转（34%对20%，P < 0.001，ES = 1.16）和超级大回转（42%对28%，P < 0.001，ES = 1.11）项目中，外侧腿的准等长模式显著长于内侧腿，但在回转项目中，内侧腿的准等长模式显著长于外侧腿（19%对11%，P < 0.001，ES = 0.64）。因此，大回转和超级大回转表现出相似性，内侧腿的膝关节离心平均角速度显著快于外侧腿（大回转 -58°·s对 -54°·s，超级大回转 -52°·s对 -45°·s，P < 0.001，ES ≥ 0.22），而回转项目则呈现相反模式（-72°·s对 -89°·s，P < 0.001，ES = 1.10）。准等长阶段在以往研究中被忽视，但却是需要考虑的关键因素。当前数据可用于训练外侧腿和内侧腿的特异性，纳入特定项目的收缩模式和练习。
