Link Daniel, Weber Marcus, Linke Daniel, Lames Martin
Department of Exercise Science and Sports Informatics, Technical University Munich, Munich, Germany.
Front Physiol. 2019 Jan 18;9:1882. doi: 10.3389/fphys.2018.01882. eCollection 2018.
This study explores whether positioning systems are a viable alternative to timing gates when it comes to measuring sprint times in ice hockey. We compared the results of a single-beam timing gate (Brower Timing) with the results of the Iceberg optical positioning system () and two radio-based positioning systems provided by InMotio () and Kinexon (). The testing protocol consisted of two 40 m linear sprints, where we measured sprint times for a 11 m subsection (), and a shuttle run (), including five 14 m sprints. The exercises were performed by six top-level U19 field players in regular ice hockey equipment on ice. We quantified the difference between measured sprint times e.g., by Mean Absolute Error (MAE) (s) and Intra Class Correlation (ICC). The usefulness of positioning systems was evaluated by using a Coefficient of Usefulness (CU), which was defined as the quotient of the Smallest Worthwhile Change (SWC) divided by the Typical Error (both in s). Results showed that radio-based systems had a higher accuracy compared to the optical system. This concerned Linear Sprint 11 (MAE = 0.16, MAE = 0.01, MAE = 0.01, ICC = 0.38, ICC = 0.98, ICC = 0.99) as well as Shuttle Total (MAE = 0.07, MAE = 0.02, MAE = 0.02, ICC = 0.99; ICC = 1.0, ICC = 1.0). In Shuttle Total, all systems were able to measure a SWC of 0.10 s with a probability of >99% in a single trial (CU = 4.6, CU = 6.5, CU = 5.1). In Linear Sprint 11 an SWC of 0.01 s might have been masked or erroneously detected where there were none due to measurement noise (CU = 0.6, CU = 1.0, CU = 1.0). Similar results were found for the turning subsection of the shuttle run (CU = 0.6, CU = 0.5, CU = 0.5). All systems were able to detect an SWC higher than 0.04 s with a probability of at least 75%. We conclude that the tested positioning systems may in fact offer a workable alternative to timing gates for measuring sprints times in ice hockey over long distances like shuttle runs. Limitations occur when testing changes/differences in performance over very short distances like an 11 m sprint, or when intermediate times are taken immediately after considerable changes of direction or speed.
本研究探讨在冰球比赛中测量短跑时间时，定位系统是否是计时门的可行替代方案。我们将单光束计时门（Brower Timing）的结果与冰山光学定位系统（）以及InMotio（）和Kinexon（）提供的两种基于无线电的定位系统的结果进行了比较。测试方案包括两次40米直线短跑，我们测量了11米子路段（）的短跑时间，以及一次穿梭跑（），包括五次14米短跑。这些练习由六名顶级U19冰球场上的球员穿着常规冰球装备在冰上进行。我们通过平均绝对误差（MAE）（秒）和组内相关系数（ICC）等指标量化了测量的短跑时间之间的差异。通过使用有用性系数（CU）来评估定位系统的有用性，该系数定义为最小有价值变化（SWC）除以典型误差（两者均以秒为单位）的商。结果表明，与光学系统相比，基于无线电的系统具有更高的准确性。这在直线短跑11（MAE = 0.16，MAE = 0.01，MAE = 0.01，ICC = 0.38，ICC = 0.98，ICC = 0.99）以及穿梭跑总时间（MAE = 0.07，MAE = 0.02，MAE = 0.02，ICC = 0.99；ICC = 1.0，ICC = 1.0）方面均有体现。在穿梭跑总时间中，所有系统在单次试验中都能够以>99%的概率测量到0.10秒的最小有价值变化（CU = 4.6，CU = 6.5，CU = 5.1）。在直线短跑11中，由于测量噪声，0.01秒的最小有价值变化可能被掩盖或错误检测（CU = 0.6，CU = 1.0，CU = 1.0）。在穿梭跑的转弯子路段也发现了类似结果（CU = 0.6，CU = 0.5，CU = 0.5）。所有系统都能够以至少75%的概率检测到高于0.04秒的最小有价值变化。我们得出结论，对于在冰球比赛中测量长距离如穿梭跑的短跑时间，经过测试的定位系统实际上可能为计时门提供一种可行的替代方案。当测试非常短距离如11米短跑的性能变化/差异时，或者当在方向或速度发生相当大变化后立即获取中间时间时，会存在局限性。
