School of Exercise Science, Australian Catholic University, Brisbane, QLD, Australia.
Int J Sports Physiol Perform. 2015 Jan;10(1):71-5. doi: 10.1123/ijspp.2014-0062. Epub 2014 Jun 6.
Bowling workload is linked to injury risk in cricket fast bowlers. This study investigated the validity of microtechnology in the automated detection of bowling counts and events, including run-up distance and velocity, in cricket fast bowlers.
Twelve highly skilled fast bowlers (mean ± SD age 23.5 ± 3.7 y) performed a series of bowling, throwing, and fielding activities in an outdoor environment during training and competition while wearing a microtechnology unit (MinimaxX). Sensitivity and specificity of a bowling-detection algorithm were determined by comparing the outputs from the device with manually recorded bowling counts. Run-up distance and run-up velocity were measured and compared with microtechnology outputs.
No significant differences were observed between direct measures of bowling and nonbowling events and true positive and true negative events recorded by the MinimaxX unit (P = .34, r = .99). The bowling-detection algorithm was shown to be sensitive in both training (99.0%) and competition (99.5%). Specificity was 98.1% during training and 74.0% during competition. Run-up distance was accurately recorded by the unit, with a percentage bias of 0.8% (r = .90). The final 10-m (-8.9%, r = .88) and 5-m (-7.3%, r = .90) run-up velocities were less accurate.
The bowling-detection algorithm from the MinimaxX device is sensitive to detect bowling counts in both cricket training and competition. Although specificity is high during training, the number of false positive events increased during competition. Additional bowling workload measures require further development.
保龄球工作量与板球快速投球手的受伤风险有关。本研究旨在探讨微技术在自动检测板球快速投球手的投球计数和事件（包括助跑距离和速度）方面的有效性。
12 名技术精湛的快速投球手（平均±SD 年龄 23.5±3.7 岁）在训练和比赛期间，穿着微技术装置（MinimaxX），在户外环境中进行了一系列投球、投掷和守备活动。通过将设备的输出与手动记录的投球计数进行比较，确定投球检测算法的灵敏度和特异性。测量助跑距离和助跑速度，并与微技术输出进行比较。
直接测量的投球和非投球事件与 MinimaxX 单元记录的真阳性和真阴性事件之间没有显著差异（P=.34，r =.99）。在训练（99.0%）和比赛（99.5%）中，投球检测算法都表现出很高的灵敏度。训练时的特异性为 98.1%，比赛时为 74.0%。该装置准确地记录了助跑距离，偏差百分比为 0.8%（r =.90）。最后 10 米（-8.9%，r =.88）和 5 米（-7.3%，r =.90）的助跑速度则不太准确。
MinimaxX 设备的投球检测算法在板球训练和比赛中都能敏感地检测投球次数。虽然在训练时特异性很高，但比赛时假阳性事件的数量增加了。需要进一步开发其他投球工作量指标。
