Fast A, Sosner J, Begeman P, Thomas M, Drukman D
Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, New York 10467, USA.
Am J Phys Med Rehabil. 1997 Sep-Oct;76(5):370-7. doi: 10.1097/00002060-199709000-00004.
The objective of this study was to determine the effect of two types of restraining belts (lap belt and a four-point belt) on an instrumented dummy during three situations: wheelchair hitting straight into curb (SIC); wheelchair falling straight off a curb (SOC); wheelchair falling diagonally off a curb (DOC). A fully instrumented (50th percentile Hybrid III) dummy was seated in a standard wheelchair and restrained with one of the belts. The wheelchair rolled down a ramp reaching a platform at 2.4 miles per hour (comfortable walking speed). Three types of experiments were performed: SIC, SOC, DOC. Each experiment was repeated at least three times. Forces, moments, and acceleration were monitored and recorded via 48 sensors placed at the head, spine, and limbs. All experiments were videotaped and photographed. The data were averaged and compared with standards that have been previously established in car crash testing and with data recently obtained in a similar study using a nonrestrained dummy. Our results showed that in the SIC experiments, low magnitude forces, moments, and acceleration of no clinical significance were recorded with both types of belts. The wheelchair remained upright and the dummy safely seated. In the SOC experiments, the two belts prevented the dummy's ejection from the chair and, thus, have been effective in lowering the forces, moments, and acceleration and preventing significant injuries to the head and neck regions. In the DOC experiments, the lap belt proved to be somewhat more effective than the four-point belt in lowering the extension forces at the upper neck and the moments at the lower neck below injury levels. It also kept the head injury criteria well below injury level. We postulate that the four-point belt was less effective because of its more extensive body fixation, which leads to concentration of moments and forces at the head and lower neck regions. The results of this study show that restraining systems can enhance the safety of wheelchair occupants in certain incidents. It has been demonstrated that the lap belt is as effective as the four-point belt system in SIC and SOC incidents. In DOC falls, neither belt could prevent falls and trauma to the head and neck region. The lap belt, however, was somewhat superior. We recommend that wheelchairs be equipped with a lap belt and patients be encouraged to buckle-up while using the wheelchair outdoors.
本研究的目的是确定两种类型的约束带（腰部安全带和四点式安全带）在三种情况下对一个安装了仪器的人体模型的影响：轮椅直接撞上路边石（SIC）；轮椅直接从路边石上跌落（SOC）；轮椅斜着从路边石上跌落（DOC）。一个完全安装了仪器（第50百分位的Hybrid III型）的人体模型被安置在一辆标准轮椅上，并用其中一种安全带进行约束。轮椅从一个斜坡滚下，以每小时2.4英里（舒适的步行速度）到达一个平台。进行了三种类型的实验：SIC、SOC、DOC。每个实验至少重复三次。通过放置在头部、脊柱和四肢的48个传感器监测并记录力、力矩和加速度。所有实验都进行了录像和拍照。数据进行了平均，并与先前在汽车碰撞测试中确立的标准以及最近在一项使用无约束人体模型的类似研究中获得的数据进行了比较。我们的结果表明，在SIC实验中，两种类型的安全带记录到的力、力矩和加速度的大小都很低，没有临床意义。轮椅保持直立，人体模型安全就座。在SOC实验中，两种安全带都防止了人体模型从轮椅上被弹出，因此，在降低力、力矩和加速度以及防止头部和颈部区域受到严重伤害方面是有效的。在DOC实验中，腰部安全带在降低上颈部的伸展力和低于损伤水平的下颈部的力矩方面被证明比四点式安全带更有效一些。它还使头部损伤标准远低于损伤水平。我们推测四点式安全带效果较差是因为其对身体的固定范围更广，这导致力矩和力集中在头部和下颈部区域。本研究的结果表明，约束系统在某些事故中可以提高轮椅乘坐者的安全性。已经证明，在SIC和SOC事故中，腰部安全带与四点式安全带系统一样有效。在DOC跌落事故中，两种安全带都无法防止头部和颈部区域的跌落和创伤。然而，腰部安全带略胜一筹。我们建议轮椅配备腰部安全带，并鼓励患者在户外使用轮椅时系好安全带。
