Sport Research Center, Faculty of Physical Education and Sport, Charles University, Prague, Czech Republic.
Orthopedic Center, Children's Hospital Boston, Boston, United States of America.
PLoS One. 2018 Sep 28;13(9):e0204578. doi: 10.1371/journal.pone.0204578. eCollection 2018.
The unique foot morphology and distinctive functions facilitate complex tasks and strategies such as standing, walking, and running. In those weight-bearing activities, postural stability (PS) plays an important role. Correlations among foot type, PS, and other musculoskeletal problems that increase sport injury risk are known. However, long-term associations among the foot type, the PS, and body weight (BW) distribution are lacking. Thus, the purpose of this study was to longitudinally identify changes in foot morphology, PS, and symmetry in BW distribution during adolescence among elite male soccer players.
Thirty-five Czech elite male soccer players (age, 15.49 ± 0.61 years; BW, 64.11 ± 6.16 kg; body height, 174.62 ± 5.71 cm) underwent foot type, PS, and BW distribution measurements during 3 consecutive years (T1, T2, T3). The Chippaux-Smirak index (CSI), BW distribution, and centre of pressure (COP) displacement (total traveled way [TTW]) of each player for the preferred (PL) and non-preferred leg (NL) were acquired. Repeated-measures analysis of variance (RM ANOVA), Bonferroni´s post hoc tests, and partial eta-squared (ηp2) coefficient were used for investigating the effect of time on selected variables and effect size evaluation.
Statistically significant effect of time on CSI values (PL: F2,68 = 5.08, p < 0.01, ηp2 = 0.13 and NL: F2,68 = 10.87, p < 0.01, ηp2 = 0.24) and COP displacement values (PL: F2,68 = 5.07, p <0.01, ηp2 = 0.13; NL: F2,68 = 3.53, p <0.05, ηp2 = 0.09) for both legs over 3-years period was identified. Furthermore, the Bonferroni´s post hoc analysis revealed a significant improvement of PS values in the PL (TTWT1 = 1617.11 ± 520.22 mm vs. TTWT2 = 1405.29 ± 462.76, p < 0.05; and between TTWT1 = 1617.11 ± 520.22 mm vs. TTWT3 = 1370.46 ± 373.94, p < 0.05). Only BW distribution parameter showed no significant differences, although slightly improved over time.
We observed changes in foot typology, PS, and BW distribution in young elite male soccer players during 3 consecutive years. Results demonstrated that changes in PS and body weight distribution under the high-load sport conditions during adolescence may improve with aging, except for foot morphology. Therefore, foot morphology should be carefully monitored to minimize sport injury risk in professional young soccer players during adolescence. Further research is necessary to determine more clear associations between these parameters, soccer-related injuries, and sport performances.
独特的足部形态和独特的功能使人类能够完成站立、行走和跑步等复杂任务和策略。在这些负重活动中，姿势稳定性（Postural Stability，PS）起着重要作用。已知足部类型、PS 和增加运动损伤风险的其他肌肉骨骼问题之间存在相关性。然而，关于足部类型、PS 和体重（Body Weight，BW）分布之间的长期关联还缺乏研究。因此，本研究的目的是在青少年时期，纵向确定精英男性足球运动员的足部形态、PS 和 BW 分布的变化。
35 名捷克精英男性足球运动员（年龄 15.49 ± 0.61 岁；BW 64.11 ± 6.16kg；身高 174.62 ± 5.71cm）在连续 3 年（T1、T2、T3）期间接受足部类型、PS 和 BW 分布测量。每位运动员的 Chippaux-Smirak 指数（Chippaux-Smirak Index，CSI）、BW 分布和压力中心（Centre of Pressure，COP）位移（总行程距离[Total Traveled Way，TTW]）的 PL 和 NL 腿数据都被采集。采用重复测量方差分析（Repeated-Measures Analysis of Variance，RM ANOVA）、Bonferroni 事后检验和部分 eta 平方（ηp2）系数来评估时间对选定变量的影响和效应大小。
在 3 年期间，PL 和 NL 腿的 CSI 值（PL：F2,68 = 5.08，p < 0.01，ηp2 = 0.13；NL：F2,68 = 10.87，p < 0.01，ηp2 = 0.24）和 COP 位移值（PL：F2,68 = 5.07，p <0.01，ηp2 = 0.13；NL：F2,68 = 3.53，p <0.05，ηp2 = 0.09）均具有统计学意义的时间效应。此外，Bonferroni 事后检验分析表明，PL 的 PS 值显著提高（TTWT1 = 1617.11 ± 520.22mm 与 TTWT2 = 1405.29 ± 462.76mm，p < 0.05；与 TTWT1 = 1617.11 ± 520.22mm 与 TTWT3 = 1370.46 ± 373.94mm，p < 0.05）。尽管 BW 分布参数略有改善，但没有统计学意义。
我们观察到在连续 3 年期间，年轻的精英男性足球运动员的足部类型、PS 和 BW 分布发生了变化。结果表明，青少年时期在高负荷运动条件下 PS 和体重分布的变化可能随着年龄的增长而改善，除了足部形态。因此，应仔细监测足部形态，以最大程度地降低青少年职业足球运动员的运动损伤风险。需要进一步的研究来确定这些参数、足球相关损伤和运动表现之间更明确的关联。
