Bicycle Child Seats and Injuries:
A study from 1988 is still revealing.
Summary: Useful info on bicycle-mounted child seats, although standards and helmets have changed since it was written and our page on helmets and carriers for children has more current info.
American Journal of Diseases of the Child
Bicycle-Mounted Child Seats
James D. Sargent, MD
Injury Risk and Prevention
Magda G. Peck, ScD, PA
Michael Weitzman, MD
Little information is available about bicycle-mounted child seats despite their general use for a decade. We analyzed two existing data sets to gain information about frequency, trend, and characteristics of bicycle-mounted child seat Injuries to
children 5 years old and younger. Available data suggest an Increased frequency of these injuries, with the rate of passenger injuries rising from 17% to 28% of all reported bicycle-related injuries to children in this age group in California during the years 1977 to 1986. In a detailed sample of 52 injuries related to the use of bicycle-mounted child seats, 42 per cent occurred when the bicycle crashed or tipped over and 25 per cent occurred
when the child fell out of the seat. Sixty-five percent involved the head and face, and 27% of the head injuries were serious. Substantial morbidity associated with these injuries could be ameliorated if children using these seats wore appropriate bicycle helmets.
Despite the general use of bicycle-mounted child seats for a decade, data regarding their safety are sparse in the extensive literature on bicycle-related injuries. The seats are mentioned in only two   major pediatric texts. The American Academy of Pediatrics issued a child-safety slip containing guidelines for parents in 1985 and only briefly addresses these seats in its 1987 injury manual.  We were unable to identify any published data on the frequency or severity of injury associated with
bicycle-mounted child seats with the exception of an abstract presented to the Ambulatory Pediatric Association in which Tanz and Christoffel. described the nationwide incidence of injuries related to the use of bicycle-mounted child seats based on Consumer Product Safety Commission data.
Herein, we report data from two known sources that are relevant to injuries related to bicycle-mounted child seats. We describe the frequency and characteristics of these injuries and suggest specific preventive measures.
MATERIALS AND METHODS
Since 1977, California has had a statewide traffic injury surveillance system operated by the state's highway patrol. In this system, state and local law enforcement officers are mandated to complete a standardized report on all traffic-related injuries. The reports are sent to a centralized data collection agency From 1977 to 1982, bicycle-related injuries were reported
only if they were associated with a motor vehicle. Since 1983, all traffic-associated injuries, irrespective of whether they involve motor vehicles and including all bicycle-related injuries that occur on public property, must be reported. We examined available information by age on the number of injuries to and deaths of bicycle riders and bicycle passengers in the entire state of California during the ten-year period from 1977
through 1986. Although this system is unable to provide information specific to bicycle-mounted child seats, we used the data to draw inferences about the frequency of these injuries over time as well as to describe the proportion of total bicycle-related injuries that occur to passengers 5 years of age and under.
We also examined data from the Consumer Product Safety Commission, Washington, DC, which collects injury data from a representative sample of 62 emergency departments across the nation as part of its National Electronic Injury Surveillance
System. These data delineate frequency distributions of several variables specific to injuries related to bicycle-mounted child seats for the eight-year period from 1979 through 1986, including type of injury, mechanism of injury, and frequency of hospitalization.
We conducted secondary data analysis on these two existing data sets on bicycle-related injuries.
California Highway Patrol Data
There were 2439 bicycle-related injuries
and 24 deaths of children 5 years of age or under reported by California traffic authorities during the period from 1977 through 1986. The majority of bicycle-related injuries (73%) and deaths (84%) occurred among 5-year-old children. Among 4- and 5-year-old children, most bicycle-related injuries occurred among bicycle operators (74% for 4-year-old children, 91% for 5-year-old children). In sharp contrast, injuries to passengers represent 97% to 99% of all bicycle-related injuries among children 3 years of age or younger (Table 1). During this period the number of injuries involving riders showed little change from year to year, while the number of injuries to passengers doubled, raising the proportion of injuries involving passengers from 17% in 1977 to 28% in 1986 for children 5 years old or younger (Table 2). Among the 24 bicycle-related deaths reported in this age group, 23 were of riders and only one was of a passenger.
National Electronic Injury Surveillance System
Fifty-four injuries in children riding bicycle-mounted child seats were reported to the National Electronic Injury Surveillance System from the participating emergency departments between the years 1979 and 1986. Fifty two (96%) involved children 5 years old and younger. In this series, the head or face was injured in 65% of all children 5 years old or younger who were in bicycle-mounted child seats. As shown in Table 3, the principal trauma site in 22 (42%) of the 52 patients was the head. Serious head injury (concussion, internal organ injury, fracture) was reported in six children, and included 12% of all reported injuries and 27% of head injuries The remaining
injuries included minor head injuries, such as lacerations, Hematoma contusions, or abrasion The face was the principal site of injury in 12 children (23%). The remaining injuries involved the extremities, with the majority in the lower portion
of the legs, ankles, and feet. There were two fractures reported.
Bicycle Passengers and Riders
by Age in California:
Number followed by (%)
Ages, Passengers Riders Total
0-1 73 (97.4) 2 (2.6) 75 (100.0)
2 99 (99.0) 1 (0.9) 100 (100.0)
3 106 (99.1) 1 (0.9) 107 (100.0)
4 100 (26.0) 285 (74.0) 385 (100.0)
5 166 (9.4) 1606 (90.6) 1772 (100.0)
0-5 544 (22.3) 1895 (79.7) 2439 (100.0)
Source: California Highway Patrol, Information
Management Section, Sacramento, 1987.
Number followed by (%)
Bicycle-Related Injuries to Children
5 years Old and Under in California:
Year Passengers Riders Total
1977 38 (16.6) 190 (83.4) 228 (100)
1978 48 (19.2) 202 (80.8) 250 (100)
1979 49 (22.7) 167 (77.3) 216 (100)
1980 45 (20.8) 171 (79.2) 216 (100)
1981 56 (25.8) 161 (74.2) 217 (100)
1982 47 (20.3) 184 (79.7) 231 (100)
1983 44 (19.1) 186 (80.9) 230 (100)
1984 65 (24.2) 204 (75.8) 268 (100)
1985 72 (24.5) 221 (75.5) 293 (100)
1986 80 (27.7) 209 (72.3) 299 (100)
1977-1986 544 (22.3) 1895 (77.7) 2439 (100)
Source: California Highway Patrol
Information Management Section
Number followed by (%) of Injuries
Selected Characteristics of Bicycle-Mounted Child Seats
Injuries to Children 5 Years Old and Under- 1979-1986.
Site of Injury
Head 22 (42.3)
Face 12 (23.1)
Feet or ankles 11 (21.1)
Upper extremity 4 (7.7)
Other 3 (5.8)
Subtotal 52 (100.0)
Severity of head injuries
Concussion 4 (18.3)
Internal organ injury 1 (4.5)
Fracture 1 (4.5)
Hematoma 1 (4.5)
Laceration 2 (9.1)
Contusion and abrasion 12
Other 1 (4.5)
Subtotal 22 (100.0)
Source: National Electronic Injury Surveillance
System, Consumer Product Safety Commission, Washington. DC, 1987.
Twenty-two (42%) of the injuries related to bicycle-mounted child seats that were reported to the National Electronic Injury Surveillance System occurred when the bicycle crashed or tipped over. Thirteen (25%) occurred when children fell from the bicycle-mounted child seat, four (8%) occurred when the seat detached from the bicycle, and 12 (23%) occurred when an extremity was caught in spokes of the wheel.
Hospitalization was required in four (8%) of the 52 children 5 years old and younger who had bicycle-mounted child seat-related injuries and who presented to the emergency departments participating in the National Electronic Injury Surveillance system.
1. Do not transport children under 1 year or over 40 lb in a bicycle-mounted child seat
Ten Basic Rules for Safe Use of
Bicycle-Mounted Child Seats
2. The passenger always should wear a crash-tested helmet when transported in a bicycle-mounted child seat.
3. The passenger always should be belted into the child seat.
4. The child seat should include spoke protectors for the child's feet.
5. The child seat should be mounted on the rear wheel.
6. The back of the seat should be
high enough to provide adequate head support for the child.
7. The seat should be installed at a bicycle shop by an experienced person
8. Always lean the bicycle against a wall for stability when the rider or the child mounts or dismounts.
9. Recognize that, when transporting a child in a child seat, bicycles require a longer braking distance, are less maneuverable, and are prone to swerve when the child moves suddenly
10. Never leave a child unattended in a bicycle-mounted child seat.
Bicycle-mounted child seats have become increasingly popular in the past decade. Industry sources estimate an increase in sales from 150 000 in 1977 to more than 1 million in 1987 (Richard Timms, MD, written communication, Aug 31, 1987). Although the data from the California Highway Patrol do not directly address injuries related to bicycle-mounted child seats, the marked increase in the number of injuries to passengers reported from 1977 to 1986 may be indicative of an increase in the number of these injuries. Sales and, hence, use of these seats similarly increased in a corresponding time period. Alternatively, the sustained upward trend since 1983 may be a data artifact of the
introduction of more liberal rules for reporting in that year. However, this reporting bias cannot explain why passenger injuries comprise a greater proportion of total bicycle-related injuries in 1986 (28%), compared with 1983 (19%); one would expect reporting bias to affect the numbers of both rider and passenger injuries equally. Nonetheless, injuries to bicycle passengers represent almost one third of all bicycle-associated
injuries in this age group and are thus worthy of our closer consideration.
The Consumer Product Safety Commission uses its surveillance data to make nationwide injury projections. From the 52 reported cases of bicycle-mounted child seat-related injuries in the group of children 5 years old and younger, the commission has estimated that 3450 such injuries occurred during the eight-year reporting period. This seemingly small number may be a consequence of underreporting of these injuries due to a
lack of standardized reporting methods used by participating emergency departments (A. McDonald, oral communication, October 1987). While these projections should be interpreted with caution because of the small sample size, they do provide one estimate of the magnitude of bicycle-mounted child seat-related injuries nationwide.
There are several factors that contribute to the observation that a large proportion of bicycle-mounted child seat-related injuries involve the head and face. Properly mounted, these devices place the child's head some 1.2 to 1.5 m above the road surface, high enough to impart a significant blow to the child who falls off. The child who is properly belted in may be at even
greater risk for head injury when the bicycle tips over: the head describes an arc with a 1.5-m radius and impact must absorb both the momentum of the child and the bicycle. This is compounded by the fact that infants and toddlers have relatively large heads and poorly developed neck and upper body musculature that is incapable of modifying this force to any substantial degree. The seat design provides virtually no head protection,
which is especially problematic in that the majority of bicycle-related injuries are accompanied by substantial laterally projected forces when the bicycle falls over.
Widespread use of bicycle helmets among children transported in bicycle-mounted child seats could significantly reduce the frequency and severity of head injuries. The concept that helmet use prevents serious head injury is well documented in the case of motorcycles,. but documentation is unavailable for bicycles. Barriers to helmet use include high cost, lack of education and advertising, and low public awareness; thus, bicycle helmets have yet to gain wide popularity in the United States.. In addition, the development of bicycle-mounted child seats has preceded the development of adequate headgear for infants and young children. This situation is further complicated by the lack of uniform standards for infant helmets, many of which have never been crash tested. In the past few years, however, better headgear for children has become available.  Several infant helmets now
conform to the 1984 Snell Standards for bicycle helmets, which are generally accepted as the most rigorous test standards in general use today. A description of the Snell bicycle helmet standards can be obtained from the Snell Memorial Foundation 
We offer the following recommendations. Clinicians should question parents about bicycle habits and recognize that bicycle enthusiasts may wish to introduce their children to the pleasures of the sport or transport their children in bicycle-mounted child seats. Parents should be made aware of the risks involved with these carriers, especially the possibility of severe head injury. Those parents who indicate that they are likely to use
these carriers can then be provided with the 1985 American Academy of Pediatrics child safety slip entitled The
Child as a Passenger on an Adult's Bicycle and a list of safe helmets. In general, helmets that do not bear the Snell or American National Standards Institute safety stickers have not been crash tested and may not be adequate. Table 4 combines a synthesis of the 1985 American Academy of Pediatrics recommendations and several suggestions generated by the data examined in this study.
We suggest that these injuries are substantial and severe enough to warrant further investigation and better surveillance methods.
We thank John Howland, Ph.D., and Marie Bond, EdM, for their thoughtful comments, Margaret Stanhope for the preparation of this manuscript, and Jim Fremont of the Bicycle Federation of America, Washington DC. Our information-gathering was greatly facilitated by Beverly Christ of the California Highway Patrol, Sacramento, and Drucilla Besley of the Consumer Product Safety Commission, Washington, DC.
A comprehensive list of helmets approved by both the American National Standards Institute and the Snell Memorial Foundation is available through the Bicycle Federation of America at the following address: Infant Helmets, Bicycle Federation of America.
 Behrman RE, Vaughan VC: Nelson Textbook of Pediatrics, ed. 13. Philadelphia, WB
Saunders Co, 1987.
 Hoekelman RA, Blatman S, Friedman SB, et a1: Primary Pediatric Care. St Louis, CV Mosby Co, 1987.
 McIntire M, Greenshur J, Bass J: Injury
Control Manual for Children and Youth. Evanston, IL, American Academy of Pediatrics, Committee on Accident and Poison Prevention, 1987.
 Tanz RR, Christoffel KK: Childhood injuries due to bicycle-mounted child
seats, abstracted. American Journal of Diseases of the Child 1986;40:319.
 McSwain NE Jr Petrucelli E: Medical consequences of motorcycle helmet nonusage. Journal of Trauma 1984;24:23-236.
 Weiss BD: Bicycle helmet use by children. Pediatrics 1986;77:677-679.
 James HE, Buchta R, Stein M: A multipurpose infant helmet. Concepts Pediatric Neurosurgery 1985;5:41-47.
1984 Standard for Protective Headgear for Use in
Bicycling. Snell Memorial Foundation. 1984.
AJDC-Vol 142, July 1988 Bicycle-Mounted Child
Seats-Sargent et al
Accepted for publication April 13, 1988.
From the Department of Pediatrics Boston City Hospital, Boston University School of Medicine and Public Health (Drs Sargent and Weitzman); and the Department of Community Health Service, City of Boston (Dr Peek).
Reprint requests to HOB 421, Boston City Hospital,
818 Harrison Ave, Boston, MA 02118 (Dr Weitzman).