Departament of Physical Education, Universidade Federal do Parana, Curitiba, Parana, Brazil.
Faculty of Physical Education, Universidade de Brasilia, Brasilia, Distrito Federal, Brazil.
PLoS One. 2020 Mar 19;15(3):e0229918. doi: 10.1371/journal.pone.0229918. eCollection 2020.
Although swimming is recognized as a symmetrical sport, equivalence between each body side cannot be insured. Swimmers with physical and motor impairment may present asymmetries that are even more pronounced. Therefore, the objective of this study was to assess the symmetry of temporal coordination in the front crawl stroke phases and their dimensional characteristics among swimmers of different levels of skill and disabled swimmers. Forty-one swimmers (28 men and 13 women, 18,8 ± 3,3 years, divided 21 of them into groups of high and low level of skill and 20 in disabled swimmers group) performed a 50m maximum of front-crawl test while they were recorded by six synchronized cameras (four underwater and two above water) for analysis of the stroke phases, stroke dimensions (anteroposterior, mediolateral and vertical amplitude), index of coordination and hand speed. The symmetry index was calculated by the difference between the right and the left strokes. Comparisons were made using the Kruskal-Wallis test and multivariate comparisons were made using the Mann-Whitney test, with p <0.05. Asymmetry was noted in anteroposterior and mediolateral amplitudes of the stroke, index of coordination, duration of the recovery phase, each of the underwater phases and in the hand speed during the downseep phase, regardless of the level of skill or impairment. The disabled swimmers also showed asymmetry in the vertical amplitude of the stroke as well as in the insweep and upsweep speed. The reasons for these asymmetries may be the preference for unilateral breathing, force imbalance between pairs of homologous muscles and motor control deficit. The training with stereotypic movements may explain the similarity of asymmetries among the different groups of swimmers.
尽管游泳被认为是一项对称运动，但无法保证每个身体侧面的均衡。身体和运动能力受损的游泳运动员可能会表现出更明显的不对称性。因此，本研究的目的是评估不同技能水平的游泳运动员和残疾游泳运动员的前爬泳划水阶段时间协调性的对称性及其维度特征。41 名游泳运动员（28 名男性和 13 名女性，18.8±3.3 岁，其中 21 名分为高技能组和低技能组，20 名分为残疾游泳运动员组）进行了 50m 最大前爬泳测试，同时使用六台同步摄像机（四台水下和两台水上）对划水阶段、划水尺寸（前后向、内外向和垂直幅度）、协调指数和划手速度进行分析。对称性指数通过左右划水的差值计算。使用 Kruskal-Wallis 检验进行比较，使用 Mann-Whitney 检验进行多变量比较，p<0.05。无论技能水平或损伤程度如何，都注意到划水的前后向和内外向幅度、协调指数、恢复阶段的持续时间、水下阶段的每个阶段以及下降阶段的划手速度存在不对称性。残疾游泳运动员在划水的垂直幅度以及内划和上划速度方面也表现出不对称性。这些不对称的原因可能是单侧呼吸的偏好、同源肌肉之间的力量不平衡以及运动控制缺陷。刻板运动的训练可能解释了不同游泳运动员群体之间不对称性的相似性。
