Head acceleration events (HAEs) are acceleration responses of the head following external short-duration collisions. The potential risk of brain injury from a single high-magnitude HAE or repeated occurrences makes them a significant concern in sport. Instrumented mouthguards (iMGs) can approximate HAEs. The distinction between sensor acceleration events, the iMG datum for approximating HAEs and HAEs themselves, which have been defined as the in vivo event, is made to highlight limitations of approximating HAEs using iMGs. This article explores the technical limitations of iMGs that constrain the approximation of HAEs and discusses important conceptual considerations for stakeholders interpreting iMG data. The approximation of HAEs by sensor acceleration events is constrained by false positives and false negatives. False positives occur when a sensor acceleration event is recorded despite no (in vivo) HAE occurring, while false negatives occur when a sensor acceleration event is not recorded after an (in vivo) HAE has occurred. Various mechanisms contribute to false positives and false negatives. Video verification and post-processing algorithms offer effective means for eradicating most false positives, but mitigation for false negatives is less comprehensive. Consequently, current iMG research is likely to underestimate HAE exposures, especially at lower magnitudes. Future research should aim to mitigate false negatives, while current iMG datasets should be interpreted with consideration for false negatives when inferring athlete HAE exposure.

头部加速事件 (HAE) 是外部短时碰撞后头部的加速响应。单次高强度HAE或重复发生造成脑损伤的潜在风险使它们成为体育运动中的一个重要问题。仪器化护齿套 (iMG) 可以近似 HAE。传感器加速事件、用于近似HAE的iMG数据和被定义为体内事件的HAE本身之间的区别是为了强调使用iMG近似HAE的局限性。本文探讨了 iMG 的技术限制，这些限制限制了 HAE 的近似，并讨论了利益相关者解释 iMG 数据的重要概念考虑因素。传感器加速事件对 HAE 的近似受到误报和漏报的限制。当尽管没有（体内）HAE 发生而记录传感器加速事件时，会发生误报，而当（体内）HAE 发生后未记录传感器加速事件时，会发生误报。多种机制会导致误报和漏报。视频验证和后处理算法提供了消除大多数误报的有效方法，但误报的缓解措施不太全面。因此，当前的 iMG 研究可能会低估 HAE 暴露，尤其是在较低量级的情况下。未来的研究应旨在减少假阴性，而当前的 iMG 数据集在推断运动员 HAE 暴露时应考虑假阴性。