School of Health and Sport Sciences, University of the Sunshine Coast, Maroochydore DC, QLD 4558, Australia.
J Sci Med Sport. 2012 Mar;15(2):169-74. doi: 10.1016/j.jsams.2011.09.002. Epub 2011 Oct 21.
The aim of this study was to evaluate changes in the three dimensional lower limb kinematics during a simulated cycling time trial.
Repeated measures.
Ten experienced male road cyclists performed a 60 min cycling test at a workload based on previous onset of blood lactate accumulation (OBLA) testing. The time trial (TT) was divided into six 10 min periods consisting of 8 min cycling at steady state (88% of OBLA) followed by a 90 s effort phase (140% of OBLA) and a 30 s recovery phase (60% of OBLA). Three-dimensional kinematic data (200 Hz) were recorded in the last minute of each steady state phase with specific attention directed at changes in range of motion (ROM) and consistency of orientation at the hip, knee and ankle joints during drive phase.
from repeated measures ANOVA indicated a mean effect for test duration on the drive phase ROM in both hip extension (p=0.027) and ankle dorsi flexion (p<0.001). The SD of the mean tibial rotation during the drive phase was the only measure of movement consistency that showed an effect for test duration (p=0.031).
These findings indicated that participants tended to increase the ROM in hip extension and ankle flexion during drive phase at the end of a TT. Changes in the consistency of tibial rotation during the drive phase may be an important indicator of fatigue and should be monitored by coaches during training due to its possible relationship with injury and fatigue.
本研究旨在评估模拟自行车计时赛过程中三维下肢运动学的变化。
重复测量。
10 名经验丰富的男性公路自行车运动员在基于先前血乳酸积累起始（OBLA）测试的工作量下进行 60 分钟的自行车测试。计时赛（TT）分为六个 10 分钟的周期，每个周期包括 8 分钟的稳态骑行（88%的 OBLA），接着是 90 秒的努力阶段（140%的 OBLA）和 30 秒的恢复期（60%的 OBLA）。在每个稳态阶段的最后一分钟记录三维运动学数据（200Hz），特别关注在驱动阶段髋关节、膝关节和踝关节的运动范围（ROM）和方向一致性的变化。
重复测量方差分析表明，测试持续时间对髋关节伸展（p=0.027）和踝关节背屈（p<0.001）的驱动阶段 ROM 有均值效应。在驱动阶段，胫骨旋转的均方根标准差是唯一显示测试持续时间效应的运动一致性度量（p=0.031）。
这些发现表明，参与者在 TT 结束时，在驱动阶段倾向于增加髋关节伸展和踝关节背屈的 ROM。驱动阶段胫骨旋转一致性的变化可能是疲劳的一个重要指标，由于其可能与损伤和疲劳有关，因此应在训练中由教练进行监测。
