Menon Rajiv, Ghati Yoganand
The Center for Injury Research and Prevention, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.
Annu Proc Assoc Adv Automot Med. 2007;51:129-54.
This study was initiated to quantify the effects of the misuse in LATCH lower webbing. In the short period since the implementation of the LATCH system several cases of potential misuses have been reported. A series of sled tests in frontal impact mode were conducted with various misuse conditions (loose attachment of LATCH lower webbing, misrouting of LATCH lower webbing and child seat back inclination) for both forward and rearward facing child safety seats (FFCSS and RFCSS). Results from these tests are compared and discussed with that of the standard test with no misuse and showed that as the slack in the lower LATCH webbing increased, ATD injury measures exceeded the limits. The FFCSS tests in the reclined condition yielded lower injury values for all except the chest G's when compared to the standard upright test. In the misrouting tests the ATD kinematics depended on the routing pivot point, the lower the pivot point the better the ATD kinematics. Similar findings were also observed in the RFCSS tests. The use of top tether with the FFCSS substantially improved the performance of the Hybrid III 3 year old ATD in spite of misuse conditions and the injury values were lower than the corresponding tests with no top tether. The effective reduction was 37% in the HIC values, 6% in the chest G's, 30% in the head excursion, 22 % in the knee excursion and finally 37 % reduction in the Nij values.
本研究旨在量化儿童安全座椅下固定连接（LATCH）下固定带使用不当的影响。自LATCH系统实施后的短时间内，已有多起潜在使用不当的案例被报道。针对正向和反向儿童安全座椅（FFCSS和RFCSS），在正面碰撞模式下进行了一系列雪橇试验，试验设置了各种使用不当的情况（LATCH下固定带连接松动、LATCH下固定带布线错误以及儿童座椅靠背倾斜）。将这些试验结果与无使用不当情况的标准试验结果进行了比较和讨论，结果表明，随着LATCH下固定带松弛度增加，假人损伤指标超过了限值。与标准直立试验相比，FFCSS在倾斜状态下的试验除胸部加速度外，其他各项损伤值均较低。在布线错误试验中，假人的运动学表现取决于布线枢轴点，枢轴点越低，假人的运动学表现越好。在RFCSS试验中也观察到了类似的结果。尽管存在使用不当的情况，但在FFCSS上使用顶部系绳能显著改善3岁混合III型假人的性能，且损伤值低于未使用顶部系绳的相应试验。头部损伤指标（HIC）值有效降低了37%，胸部加速度降低了6%，头部偏移量降低了30%，膝盖偏移量降低了22%，颈部损伤指标（Nij）值最终降低了37%。
