Sindall Paul, Lenton John P, Whytock Katie, Tolfrey Keith, Oyster Michelle L, Cooper Rory A, Goosey-Tolfrey Victoria L
The University of Salford, Salford, UK.
J Spinal Cord Med. 2013 Jul;36(4):383-93. doi: 10.1179/2045772312Y.0000000068.
To compare the criterion validity and accuracy of a 1 Hz non-differential global positioning system (GPS) and data logger device (DL) for the measurement of wheelchair tennis court movement variables.
Initial validation of the DL device was performed. GPS and DL were fitted to the wheelchair and used to record distance (m) and speed (m/second) during (a) tennis field (b) linear track, and (c) match-play test scenarios. Fifteen participants were monitored at the Wheelchair British Tennis Open.
Data logging validation showed underestimations for distance in right (DLR) and left (DLL) logging devices at speeds >2.5 m/second. In tennis-field tests, GPS underestimated distance in five drills. DLL was lower than both (a) criterion and (b) DLR in drills moving forward. Reversing drill direction showed that DLR was lower than (a) criterion and (b) DLL. GPS values for distance and average speed for match play were significantly lower than equivalent values obtained by DL (distance: 2816 (844) vs. 3952 (1109) m, P = 0.0001; average speed: 0.7 (0.2) vs. 1.0 (0.2) m/second, P = 0.0001). Higher peak speeds were observed in DL (3.4 (0.4) vs. 3.1 (0.5) m/second, P = 0.004) during tennis match play.
Sampling frequencies of 1 Hz are too low to accurately measure distance and speed during wheelchair tennis. GPS units with a higher sampling rate should be advocated in further studies. Modifications to existing DL devices may be required to increase measurement precision. Further research into the validity of movement devices during match play will further inform the demands and movement patterns associated with wheelchair tennis.
比较1赫兹非差分全球定位系统（GPS）和数据记录器设备（DL）在测量轮椅网球场运动变量方面的标准效度和准确性。
对DL设备进行初步验证。将GPS和DL安装在轮椅上，用于记录在（a）网球场、（b）直线跑道和（c）比赛测试场景中的距离（米）和速度（米/秒）。在英国轮椅网球公开赛上对15名参与者进行了监测。
数据记录验证显示，当速度>2.5米/秒时，右侧（DLR）和左侧（DLL）记录设备的距离存在低估。在网球场测试中，GPS在五项训练中低估了距离。在向前移动的训练中，DLL低于（a）标准值和（b）DLR。反转训练方向显示，DLR低于（a）标准值和（b）DLL。比赛中GPS的距离和平均速度值显著低于DL获得的等效值（距离：2816（844）米对3952（1109）米，P = 0.0001；平均速度：0.7（0.2）米/秒对1.0（0.2）米/秒，P = 0.0001）。在网球比赛中，DL观察到更高的峰值速度（3.4（0.4）米/秒对3.1（0.5）米/秒，P = 0.004）。
1赫兹的采样频率过低，无法准确测量轮椅网球运动中的距离和速度。在进一步研究中应提倡使用更高采样率的GPS设备。可能需要对现有DL设备进行改进以提高测量精度。对比赛中运动设备效度的进一步研究将为与轮椅网球相关的需求和运动模式提供更多信息。
