Relationship between cervical spine injury and helmet use in motorcycle road crashes.

Motorcycle helmets have been proven to prevent head injury and reduce fatality in road crashes. However, certain studies indicate that the helmet increases the mass to the head, and thus the potential of neck injury due to the flexion/extension of the head-neck segment in a road crash may increase. This study was conducted to evaluate the effects of motorcycle helmets and the ways in which the accidents that occurred affected the incidence of cervical spine injury. Nevertheless, it is not intended to and does not discredit the fact that helmet use prevents many motorcyclists from sustaining serious and fatal head injuries. A total of 76 cases were collected and analyzed based on the data collected from real-world crashes. The Abbreviated Injury Scale (AIS) was used to assess the severity of injury, whereas the statistical Pearson χ(2) correlation method was used for analysis. The results showed that motorcycle helmets did not affect the severity of cervical spine injury. However, when the samples were further subcategorized into different crash modes, it was found that helmets affect the incidence of a severe cervical spine injury. In frontal collisions, the use of helmets significantly reduces the severity of cervical spine injury, whereas in rear-end, side impact, and skidded accidents, the use of helmets increases the probability of a severe cervical spine injury. However, in the latter crash modes, a motorcyclist without a helmet will have to trade-off with head injury. A logistic regression model has been developed with respective crash modes and the probabilities of risk in having severe cervical spine injury have been calculated. Future designs in motorcycle helmets should therefore consider the significance of nonfrontal accidents and the interaction of helmet with other parts of the body by possibly considering the weight of the helmet.

Mechanisms of cervical spine injuries for non-fatal motorcycle road crash.

Cervical spine injuries such as subluxation and fracture dislocation have long been known to result in severe consequences, as well as the trauma management itself. The injury to the region has been identified as one of the major causes of death in Malaysian motorcyclists involved in road crashes, besides head and chest injuries (Pang, 1999). Despite this, cervical spine injury in motorcyclists is not a well-studied injury, unlike the whiplash injury in motorcar accidents. The present study is a retrospective study on the mechanisms of injury in cervical spine sustained by Malaysian motorcyclists, who were involved in road crash using an established mechanistic classification system. This will serve as an initial step to look at the cervical injuries pattern. The information obtained gives engineer ideas to facilitate design and safety features to reduce injuries. All cervical spine injured motorcyclists admitted to Hospital Kuala Lumpur between January 1, 2000 and December 31, 2001 were included in the present study. Based on the medical notes and radiological investigations (X-rays, CT and MRI scans), the mechanisms of injuries were formulated using the injury mechanics classification. The result shows that flexion of the cervical vertebrae is the most common vertebral kinematics in causing injury to motorcyclists. This indicates that the cervical vertebrae sustained a high-energy loading at flexion movement in road crash, and exceeded its tolerance level. The high frequency of injury at the C5 vertebra, C6 vertebra and C5-C6 intervertebral space are recorded. Classification based on the Abbreviated Injury Scale (AIS) is made to give a view on injury severity, 9.1% of the study samples have been classified as AIS code 1, 51.5% with AIS 2 and 21.2% with AIS 3.