Cronin John B, Templeton Rebecca L
School of Exercise, Biomedical and Health Sciences, Edith Cowan University, Joondalup, Australia.
J Strength Cond Res. 2008 Jan;22(1):318-20. doi: 10.1519/JSC.0b013e31815fa3d3.
Timing light systems are commonly used to measure sprint times of athletes. In this study, the reliability and effect of timing light height on sprint times was investigated. Two sets of timing lights set at hip and shoulder height, simultaneously timed subjects over 10 and 20 meters. The within-trial variation of both timing light heights were equally consistent; all coefficients of variation (CV) less than 1.2% with less variability associated with the longer (20 m) distances (CV < 0.85%). The typical error between the two timing light heights for both distances was small (< or = 1.3%). The mean difference between the two heights was significantly different (0.7 second, 95% CL = 0.05-0.10 second) at both the 10 and 20 m distances. Faster times were recorded at hip height as opposed to shoulder due to the legs breaking the beam before the upper body. It is suggested that standardized procedures are necessary for speed assessment using timing lights in order for comparisons to be made between athletic populations.
计时灯光系统通常用于测量运动员的短跑时间。在本研究中，研究了计时灯光高度对短跑时间的可靠性和影响。两组分别设置在臀部和肩部高度的计时灯光，同时对受试者进行10米和20米的计时。两种计时灯光高度在试验中的变化同样一致；所有变异系数（CV）均小于1.2%，且较长距离（20米）的变异性较小（CV<0.85%）。两个距离上两种计时灯光高度之间的典型误差较小（≤1.3%）。在10米和20米距离处，两种高度之间的平均差异均显著（0.7秒，95%CI=0.05-0.10秒）。由于腿部在上半身之前穿过光束，与肩部高度相比，在臀部高度记录到的时间更快。建议使用计时灯光进行速度评估时需要标准化程序，以便在不同运动员群体之间进行比较。
