Motorcycle-related Injuries to Children and Adolescents

Monash University Accident Research Centre - Report #56 - 1994

Authors: N. Haworth, J. Ozanne-Smith, B. Fox & I. Brumen

Full report in .pdf format [4.4MB]

Abstract:

This study is an exploratory one, aiming to assess the magnitude of the problem of motorcycle-related injuries (both on- and off-road) to children and adolescents, to characterise the crashes and resulting injuries and to suggest possible countermeasures.

Analyses of hospital admission data (Victorian Inpatient Minimum Dataset - VIMD) showed that Police-reported data account for only 80.4% for 18-20 year old motorcyclists involved in on-road crashes and only 37.4% for under 18 year olds in on-road crashes. On- and off-road crashes were each responsible for a total of more than 4000 hospital bed-days in Victoria in 1991 This comprised 2822 and 1282 hospital bed-days for on- and off-road injuries, respectively. From information derived from the Victorian Injury Surveillance System (VISS) and the @, it is estimated that motorcycle injuries to riders and passengers aged under 21 result in 1868 presentations to Emergency Departments in Victorian hospitals per year.

Earlier research into factors contributing to crash occurrence and injury severity and injuries resulting from motorcycle crashes are reviewed. The results of a follow-up study of 185 injured motorcyclists are presented. Possible countermeasures to reduce crash occurrence or injury severity discussed include those which reduce the severity of injury (helmets, lower limb protection, protective clothing, airbags) and those which reduce the risk of a crash occurring (conspicuity improvements, training for motorcyclists and car drivers, restrictions on off-road riding, alcohol restrictions and vehicle improvements).

Executive Summary

This study is an exploratory one, aiming to assess the magnitude of the problem of motorcycle-related injuries (both on- and off-road) to children and adolescents, to characterise the crashes and resulting injuries and to suggest possible countermeasures.

Mass data analyses

Both nationally and in Victoria, the absolute numbers of motorcyclists killed in on-road crashes has been dropping. The proportion of all road users killed who are motorcyclists has dropped nationally but Victorian data show an increase from 1989 to 1992, suggesting that different factors are affecting motorcyclists compared with other road users in this State.

Nationally, almost a quarter of all motorcyclists killed in on-road crashes are under 21 years of age. In Victoria, the figure was 38% in 1990.

Most of the motorcyclists under 21 involved in on-road crashes in Victoria in 1990-93 were over 16 but the crashes of younger riders were more severe (probably a reporting bias - see later discussion). Crashes outside of Melbourne and in higher speed zones were more severe. Overtaking and loss of control on curve crashes resulted were the most severe, Almost a quarter of intersection crashes were right-turn against. The motorcycle was travelling straight ahead in about 85% of these crashes and so was unlikely to have been at fault.

Analyses of hospital admission data (Victorian Inpatient Minimum Dataset - VIMD) showed that the reporting rate is 80.4% for 18-20 year old motorcyclists involved in on-road crashes but only 37.4% for under 18 year olds in on-road crashes. On- and off-road crashes were each responsible for a total of more than 4000 hospital bed-days in Victoria in 1991. This comprised 2822 and 1282 hospital bed-days for on- and off-road injuries, respectively.

From information derived from the Victorian Injury Surveillance System (VISS) and the V~, it is estimated that motorcycle injuries to riders and passengers aged under 21 would result in 1868 presentations to Emergency Departments in Victorian hospitals per year.

Literature review

The factors contributing to crash occurrence and injury severity were identified from the literature review as

  • being male
  • being young
  • inexperience
  • being unlicensed
  • riding a borrowed motorcycle
  • consumption of alcohol
  • riding during peak hours
  • curves
  • slippery or uneven surfaces
  • poor motorcycle maintenance

Injuries to the extremities, particularly the legs, are the most common injuries, followed by head injuries. Spinal injuries are less common but have very long-term effects. Among on-road crashes, those involving collisions result in more severe injuries than non-collision crashes. There is less information available about injury patterns in off-road crashes. However, there is some evidence of more injuries to the right side of the body, a preponderance of injuries to the extremities and head injuries when helmets are not worn. The lower speed in off-road riding may underlie the lesser severity of the resulting injuries, compared with on-road riding.

The cost of injuries in motorcycle crashes is most clearly documented for on-road crashes. Generally the cost of injuries is very high for motorcyclists, only being exceeded by the costs for pedestrians. Collision crashes have higher injury costs than non-collision crashes. The over-involvement of teenagers means that motorcycle crashes have a high cost in terms of years of potential life lost.

Throughout the literature review it is evident that much more is known about on-road crashes than off-road crashes, This underlines the need for this study.

Follow-up of hospitalised motorcyclists

The study included 174 riders and 11 pillion passengers aged under 21 years, of whom 160 were admitted to hospital and 25 were killed. About 60% of the hospitalised motorcyclists were under licensing age. Most of the motorcyclists under licensing age were injured in off-road crashes and most of the older group were injured in on-road crashes. The on-road crashes were much more likely to be fatal.

The youngest injured motorcyclists were 5 years old and most off-road motorcyclists were aged 12 to 17. The finding that 20% of the riders weighed under 50 kg suggests that their light weight may have led to difficulty in controlling the motorcycle

Most riders, even those below licensing age, had more than three years riding experience but few had any formal training. However, in almost one-fifth of the cases, the crash motorcycle was being ridden for the first time or had only been ridden once before. The involvement of lack of familiarity of the motorcycle was found for both on- and off-road crashes.

More than 40% of riders involved in on-road crashes were not licensed and more than 30% of motorcycles in on-road crashes were known to be unregistered Overall, 45% of on-road crashes involved unlicensed riding or an unregistered motorcycle.

Helmets were not worn in 14% of crashes and other protective gear was not worn in 40% of crashes. The prevalence was the same in on- and off-road crashes.

Most motorcyclists interviewed gave very high estimates of the likelihood of being injured or killed in a motorcycle crash. Many had previously been injured in a motorcycle crash. However, most intended to continue riding after recovering from their current injuries.

The most common sites for off-road crashes were motocross tracks, farms or paddocks and bush tracks. The type of crash was more commonly a collision in on-road crashes whereas loss of control was more common in off-road crashes. Natural obstacles (e.g. ditches and logs) and artificial obstacles (fences, poles, gutters, jumps on motocross tracks) were recorded as the immediate cause of most off-road crashes. Off-road collisions commonly involved other motorcycles.

Both on- and off-road crashes were more likely to occur on Saturday than any other day of the week. In accord with this, leisure was the purpose of most of the crash trips (both on- and off-road).

Not surprisingly, on-road crashes had higher estimated speeds than off-road crashes. It is important to note, however, that even at estimated speeds of less than 20 km/h, injury was severe enough to require hospitalisation.

On-road crashes were more severe (by mean Injury Severity Score) than off-road crashes and collision crashes were more severe than non-collision crashes

Head injuries were sustained by 64% of injured motorcyclists but were less common in off-road than on-road crashes. Off-road motorcyclists who wore helmets were less likely to sustain head injuries than those who did not wear helmets. Because of the small numbers not wearing helmets, this relationship could not be tested in on-road crashes. Neither were analyses of severity of injury with and without helmets possible. It was estimated that about half of the motorcyclists killed would have survived if the severity of head injury was less.

About 57% of the motorcyclists sustained one or more fractured limbs. Fractures were more common below the elbow or knee (respectively) than above. There was a tendency for off-road crashes to result in injury to limbs on the left side of the body and on-road crashes to injure limbs on the right side.

Most injured motorcyclists suffered abrasions and about half sustained contusions and lacerations. In off-road crashes, there was a trend for motorcyclists wearing protective clothing to be less likely to sustain external injuries. In on-road crashes, almost all motorcyclists sustained external injuries, whether or not protective clothing was worn.

Collision with another vehicle was the most common cause of injury for on-road crashes, followed by the impact of landing on the ground and striking roadside objects. In off-road crashes, the impact of landing on the ground was the most common cause of injury, followed by the motorcycle landing on the person. Many of the motorcycles are heavy compared to the rider's weight and this may contribute to difficulty in moving the vehicle off the body. Striking a roadside object was the most common cause of injuries resulting in death.

The countermeasures discussed include those which reduce the severity of injury (helmets, lower limb protection, protective clothing, airbags) and those which reduce the risk of a crash occurring (conspicuity improvements, training for motorcyclists and car drivers, restrictions on off-road riding, alcohol restrictions and vehicle improvements).

Recommendations to reduce motorcycle-related injuries to children and adolescents

1. Helmets should be made mandatory for off-road riding to reduce the frequency of head injuries. Further investigations of helmet performance (including retention) should be undertaken to attempt to reduce head injuries.

2. Motorcyclists be educated about the value of protective clothing and be encouraged to wear it.

3. That further investigations be conducted of when children develop the skills needed for safe motorcycle riding. In the interim, motorcycle riding by very young riders (perhaps under eight years) should be discouraged because of the likelihood of insufficient development of motor coordination,

4. Guidelines on minimum rider heights (for various styles and sizes of motorcycles) and a minimum ratio of weight of rider to weight of motorcycle be developed and distributed to retailers to advise intending purchasers and to off-road motorcycle clubs.

5. That riders be informed of the very high risks associated with riding a different motorcycle for the first (or second) time, even if they are experienced riders. The risk of riding a different motorcycle could be minimised by riding in an area free of obstacles, riding more slowly and wearing protective gear.

6. That an appropriate government authority (or authorities) take authority for off-road motorcycle safety.

7. That the extent and nature of under-reporting of on-road crashes be considered when benefit:cost ratios for countermeasures are developed.

8. Improvements to enforcement to reduce the high incidence of unlicensed riders and unregistered motorcycles in on-road crashes.

9. More widespread testing for alcohol in riders after motorcycle crashes, even if riders are young and the crash occurs off-road.

10. That parents be made aware through retailers and off-road motorcycle clubs that slowing down motorcycles for young riders will not eliminate injuries warranting hospital admission.

11. Further investigations into improving protection for the limbs is warranted because of the high incidence of fractures.

Sponsor: Victorian Health Promotion Foundation