PDF(Pubmed)
Abstract：
Head injuries are common for cyclists involved in collisions. Such collision scenarios result in a range of injuries, with different head impact speeds, angles, locations, or surfaces. A clear understanding of these collision characteristics is vital to design high fidelity test methods for evaluating the performance of helmets. We review literature detailing real-world cyclist collision scenarios and report on these key characteristics. Our review shows that helmeted cyclists have a considerable reduction in skull fracture and focal brain pathologies compared to non-helmeted cyclists, as well as a reduction in all brain pathologies. The considerable reduction in focal head pathologies is likely to be due to helmet standards mandating thresholds of linear acceleration. The less considerable reduction in diffuse brain injuries is likely to be due to the lack of monitoring head rotation in test methods. We performed a novel meta-analysis of the location of 1809 head impacts from ten studies. Most studies showed that the side and front regions are frequently impacted, with one large, contemporary study highlighting a high proportion of occipital impacts. Helmets frequently had impact locations low down near the rim line. The face is not well protected by most conventional bicycle helmets. Several papers determine head impact speed and angle from in-depth reconstructions and computer simulations. They report head impact speeds from 5 to 16 m/s, with a concentration around 5 to 8 m/s and higher speeds when there was another vehicle involved in the collision. Reported angles range from 10° to 80° to the normal, and are concentrated around 30°-50°. Our review also shows that in nearly 80% of the cases, the head impact is reported to be against a flat surface. This review highlights current gaps in data, and calls for more research and data to better inform improvements in testing methods of standards and rating schemes and raise helmet safety.
摘要：
对于参与碰撞的骑自行车的人来说，头部受伤是很常见的。这种碰撞情况会导致一系列伤害，不同的头部撞击速度，angles,地点,或表面。清楚了解这些碰撞特性对于设计用于评估头盔性能的高保真测试方法至关重要。我们回顾了详细介绍现实世界中骑车人碰撞场景的文献，并报告了这些关键特征。我们的评论表明，与非头盔自行车手相比，头盔自行车手的颅骨骨折和局灶性脑部病变大大减少，以及所有脑部病变的减少。头部病变的显着减少可能是由于头盔标准强制要求线性加速度的阈值。弥漫性脑损伤的减少程度较低可能是由于测试方法中缺乏监测头部旋转。我们对来自十项研究的1809年头部撞击的位置进行了新的荟萃分析。大多数研究表明，侧面和前部区域经常受到影响，有一个大的，当代研究强调枕骨影响的比例很高。头盔经常在边缘线附近的撞击位置较低。大多数传统的自行车头盔不能很好地保护面部。几篇论文通过深度重建和计算机模拟来确定头部撞击速度和角度。他们报告头部撞击速度从5到16米/秒，当另一辆车参与碰撞时，浓度在5到8米/秒和更高的速度。报告的角度范围从10°到80°到正常，并集中在30°-50°左右。我们的审查还显示，在近80%的案例中，据报道，头部撞击是在平坦的表面上。这篇评论强调了当前数据的差距，并呼吁进行更多的研究和数据，以更好地改善标准和评级方案的测试方法，并提高头盔的安全性。
