Brief Report






Bicycle-Related Injuries in Tehran


Mojgan Karbakhsh-Davari MD PhD*, Ali Khaji MD*, Javad Salimi MD*



Authors’ affiliation: *Sina Trauma and Surgery Research Center, Medical Sciences/Tehran University, Tehran, Iran.

•Corresponding author and reprints: Ali Khaji MD, Sina Trauma and Surgery Research Center, Sina Hospital, Medical Sciences/Tehran University, Tehran, Iran.

Telefax: +98-216-670-5503, E-mail:

Accepted for publication: 27 June 2007


Herein, we reviewed the pattern and mechanisms of injuries resulting from bicycle accidents in Tehran. During one year of trauma registry in six general hospitals, 8,000 trauma patients who had sustained injuries within a week before admission and hospitalized for more than 24 hours were studied. Bicycle injuries comprised 2.1% (n=170) of all cases admitted during the studied period. Males were injured more often than females (M:F ratio=8:1). Seventy-seven point one percent of the patients were younger than 20 years. None of the patients had used helmets while being injured. A considerable proportion of accidents occurred between 6 and 8 PM. The most common season of bicycle accidents were summer (55.2%) and spring (24.8%). Seventy-six (44.7%) patients sustained injuries in collision with other vehicles (cars, motorcycles, etc). Four patients died of severe head injuries. Thirteen (8.1%) patients had injury severity score of >16 (severe injury). The mean duration of hospital stay was 5.2 (range: 1 – 52) days.

Due to the fatal nature of head injuries and high incidence of fall/overturn injuries among bicycle riders, helmets should be worn by all riders, particularly young children. In addition, allocating a separate cycle path may reduce severe bicycle injuries.


Archives of Iranian Medicine, Volume 11, Number 1, 2008: 94 – 97.


Keywords: Bicycle accident · head injuries · helmet





ew people have any doubt that cycling has enormous health benefits,1 especially when there are increasing concerns among health professionals about the sedentary lifestyle of children and adults.2,3 Cycling is a useful form of regular exer­cise that must be carried out safely with measures to minimize the risk of injury. Each year, many people are killed or admitted to hospitals following cycling accidents.4,5 It is evident that the causes and patterns of injury and preventive measures are different in various communities. Bicycle-related injuries are a major concern in many countries.6 – 8 The objective of this study was to report bicycle-related injuries in Tehran.


Patients and Methods


The   study   population   included  trauma  patients admitted to emergency rooms (ERs) of six general hospitals in Tehran, from August 23, 1999 through September 21, 2000. These included all who sustained an injury within one week prior to  presentation  to ERs and were hospitalized for more than 24 hours. The data were collected by a questionnaire designed in Sina Trauma and Surgery Research Center. The questionnaire was completed by trained physicians visiting trauma patients in ERs and wards round the clock. Data obtained included patient’s demographics, level of prehospital care, medical and operative procedures performed in ERs and wards (coded according to ICD-10), Glasgow coma scale (GCS) and vital signs at time of presentation to ERs, injury severity score (ISS), length of hospital stay and intensive care unit (ICU) admission, if any, outcome, and source of reim­burse­ment. The injury and mechanism of accidents were classified according to ICD-9. A P<0.05 was considered statistically significant. Data analyses were performed by SPSS (version11.5).




Bicycle-related injuries accounted for 2.1% (170/8000) of all in-patient trauma patients; 170 cycling sustained 391 injuries leading to hospitalization. There were 151 (88.8%) males and 19 (11.2%) females with a male:female ratio of 8:1. The mean age was 17.7 years (range: 1 – 79).  Most of the injured patients (74.7%) aged <20 years, with a decreasing frequency of injuries in older patients. Overturn and/or fall with a rate of 53.5% (91/170), were the main causes of bicycle injury, followed by traffic accidents and collisions to fixed objects with rates of 44.7% (76/170) and 1.8% (3/170), respectively. Traffic accident was the commonest injury mechanism among males and fall/overturn was the prominent cause of injury among females (P=0.001). Types of injuries are demonstrated in Table 1. Patients injured due to traffic accidents had more severe injuries than others (P=0.001) (Table 2). Injuries were mainly (63.7%) to one of the limbs followed by head/face (26.8%) and other body regions (9.5%). Ninety-two of our patients (54.1%) had multiple injuries. Unfortunately, none of our patients had used helmets at the time of accident. Four patients died of severe head injuries. All of the deceased cases had sustained injuries in collision with motor vehicles (Table 2); three of them were <20 years old. Two patients died in the ER and two in ICU. Only six patients had a GCS <13 on admission. All of these six patients were males and injured due to traffic accidents (Table 2). Types of operative procedures are listed in Table 3. Ambulance was used only for transferring 26 patients; the remaining were transferred by private cars. Forty-six (27.1%) patients were transferred to our hospitals. A considerable proportion of accidents occurred between 6 and 8 PM. More than half of the incidents (55.2%) occurred in the summer. The lowest number of accidents occurred on the first work-day, i.e., Saturday (the weekend in Iran is Friday). The mean duration of hospital stay for our patients was 5.2 days (range: 1 – 52).


Table 1. Types of injuries among cyclists.

Kind of injury

Number (%)


147 (37.6)

Open wound   

47 (12.0)

Skull fracture (+base of skull)

10 (2.6)

Mandible+maxillary fractures 

4 (1.0)

Head injury

21 (5.4)

Head crushing injury 

1 (0.3)

Rib fracture 

2 (0.5)

Kidney injury 

3 (0.7)

Spleen injury 

1 (0.3)

Upper limb fracture   

98 (25.1)

Lower limb fracture   

44 (11.3)

Joint dislocation     

7 (1.7)

Pelvic ring fracture       

6 (1.5)




Table 2. Characteristics of patients according to mechanism of injury.




P value

Mean ISS 




Mean GCS




Head injury

22 (88%)

3 (12%)



4 (5.3%)




Table 3. Operative procedures performed in injured cyclists.

Kind of treatment

Number (%)


2 (2.3)

Repair of vessels in limbs

1 (1.2)


1 (1.2)


1 (1.2)

Closed reduction of mandible/maxilla

2 (2.3)

Closed reduction without internal fixation

35 (40.7)

Closed reduction with internal fixation

3 (3.5)

Open reduction with internal fixation

34 (39.5)

Open/closed reduction of dislocation

7 (8.1)


86 (100)


The mean ISS was 5.7 in our patients; 77.6% had mild injuries, 14.8% had moderate, and 7.6% had severe injuries.

Forty-one (24.1%) patients had sustained injury in rural areas. Patients in rural areas had significantly more severe injury (P=0.014) and head injury (27.9% vs. 10.2%) than those who injured in urban areas.


In our study, males comprised the majority of our patients with a male to female ratio of 8:1. This is in agreement with previous studies.9,10 The increased injury rate in males could be largely due to the fact that they ride more often.11 The majority of our patients aged <20 years. In literature review,10,12,13 children and adolescents comprise considerable proportion of bicycle injuries. Among our patients, overturn and/or fall from bicycle was the main cause of injury. Similar to our findings, Linn et al8 after a five-year study, also reported that loss of control/fall was the most important cause of bicycle injury in all ages. Thomas and colleagues14 also showed that most of cyclists were injured due to falling down from their bicycles.

Traffic accident—the second commonest mechanism in our setting—has been reported as the main cause of injury among cyclists in many other studies.9,12,15 Tendency of extremities to injuries, especially with severe ones, found in this study is in agreement to previous reports.16,17 Therefore, the majority of performed operative procedures were done on extremities. We would like to advise various extremity guards such as wrist-, elbow-, and knee-pads that may play a protective role. Introduction of these clothes would be neither strange nor difficult as children are used to wearing these utilities for rollerblading.

Puranik et al15 reported that all of deaths from bicycle injuries are the result of collision with motor vehicles. Ostrom et al also demonstrated that almost all (88%) victims of cycling accidents died in motor vehicle collisions.9 Some other studies found that up to 40% of collisions between bicyclists and motor vehicles are fatal for the bicyclists.18 In our study, all of cyclists’ deaths were also the result of collisions with motor vehicles. Victims of traffic accidents had severe injury and lower mean GCS than those with nontraffic injury. Restriction of children from cycling in roads and provision of appropriate tracks for their cycling could be effective ways for decreasing cycling injuries in our city. In our setting, head injury was the main cause of death among our cyclists.

Unfortunately, wearing of helmet is not mandatory for cyclists in our country. In fact, none of our patients had used helmets at the time of accident. Numerous studies demonstrated that the vast majority of bicycle-related deaths are due to head injuries.3,8,18 According to the report of Parkin et al19 in the province of Ontario, Canada, 212 bicycle injury deaths occurred between 1986 and 1991. Out of them, one third involved bicyclists <15 years of age, and three quarters of the deaths resulted from head injuries. On the other hand, it is shown that helmet could significantly prevent head injuries and reduces the associated mortality.18,20 Legislations that mandates the use of helmet for cyclists could be ratified and become effective for reduction of head injuries.

A major proportion of our patients sustained injury in urban areas. Macpherson et al6 reported that children residing in rural areas are at increased risk of hospitalization because of a bicycling-related injury, both for head and other bicycle-related injuries. This increased risk persists in areas with bicycle helmet legislation.

There are at least two limitations in our study. First, this is a hospital-based study, so we could not report the incidence of bicycle-related accidents. Conducting a community-based research in this field could add more to our knowledge regarding the accident and mechanisms of injuries. Secondly, our study did not include the information on those who died before reaching hospital, as we did not have access to prehospital data for those patients. These cases were directly referred to Legal Medicine Organization (LMO), hence, the mortality rate reported in our study probably under­estimated the real rate.

Children and adolescents comprise a great proportion of cyclists, so they are the target group for any bicycle-related injuries prevention programs. Restricting cycling in city and preparation of appropriate fields for cycling could be effective ways for decreasing cycling injuries in our city. Finally, legislation for wearing helmet and using protective devices (e.g., extremity guards) could reduce the severity of injuries and mortality. 



The authors thank Vahideh Bahrami and Somayyeh Jafari for their assistance.




1         Pucher J, Dijkstra L. Promoting safe walking and cycling to improve public health: lessons from The Netherlands and Germany. Am J Public Health. 2003; 93: 1509 – 1516.

2         Lee AJ, Mann NP. Cycle helmets. Arch Dis Child. 2003; 88: 465 – 466.

3         Gilbert K, McCarthy M. Deaths of cyclists in London 1985 – 1992: the hazards of road traffic. BMJ. 1994; 308: 1534 – 1537.

4         Li G, Baker SP. Injuries to bicyclists in Wuhan, People’s Republic of China. Am J Public Health. 1997; 87: 1049 – 1052.

5         Bostrom L, Nilsson B. A review of serious injuries and deaths from bicycle accidents in Sweden from 1987 to 1994. J Trauma. 2001; 50: 900 – 907.

6         Macpherson AK, To TM, Parkin PC, Moldofsky B,  Wright JG, Chipman ML, et al. Urban/rural variation in children’s bicycle-related injuries. Accid Anal Prev. 2004; 36: 649 – 654.

7         Roberts I, DiGuiseppi C, Ward H. Childhood injuries: extent of the problem, epidemiological trends, and costs. Inj Prev. 1998; 4 (4 suppl): S10 – 16.

8         Linn S, Smith D, Sheps S. Epidemiology of bicycle injury, head injury, and helmet use among children in British Columbia: a five-year descriptive study.  Canadian Hospitals Injury, Reporting and Prevention Program (CHIRPP). Inj Prev. 1998; 4:122 – 125.

9         Ostrom M, Bjornstig U, Naslund K, Eriksson A. Pedal cycling fatalities in northern Sweden. Int J Epidemiol. 1993; 22: 483 – 488.

10      Frank E, Frankel P, Mullins RJ, Taylor N. Injuries resulting from bicycle collisions. Acad Emerg Med. 1995; 2: 200 – 203.

11      Soori H. Epidemiology of children’s cycling injuries in Ahwaz, Islamic Republic of Iran. East Mediterr Health J. 2002; 8: 308 – 314.

12      Sacks JJ, Holmgreen P, Smith SM, Sosin DM. Bicycle-associated head injuries and deaths in the United States from 1984 through 1988. How many are preventable? JAMA. 1991; 266: 3016 – 3018.

13      Ji M, Gilchick RA, Bender SJ. Trends in helmet use and head injuries in San Diego County: the effect of bicycle helmet legislation. Accid Anal Prev. 2006; 38: 128 – 134.

14      Thomas NJ, Key JD, Ector WL. Bicycle-related head injuries in South Carolina children: what can we do to prevent them? J S C Med Assoc. 1994; 90: 355 – 359.

15      Puranik S, Long J, Coffman S. Profile of pediatric bicycle injuries. South Med J. 1998; 91: 1033 – 1037.

16      Schwartz HJ, Brison RJ. Bicycle-related injuries in children: a study in two Ontario emergency departments, 1994. Chronic Dis Can. 1996; 17: 56 – 62.

17      Maimaris C, Summers CL, Browning C, Palmer CR. Injury patterns in cyclists attending an accident and emergency department: a comparison of helmet wearers        and non-wearers. BMJ. 1994; 308: 1537 – 1540.

18      Weiss BD. Bicycle-related head injuries. Clin Sports Med. 1994; 13: 99 – 112.

19      Parkin PC, Khambalia A, Kmet L, Macarthur C. Influence of socioeconomic status on the effectiveness of bicycle helmet legislation for children: a prospective observational study. Pediatrics. 2003; 112: e192 – e196.

20      Heng KW, Lee AH, Zhu S, Tham KY, Seow E. Helmet use and bicycle-related trauma in patients presenting to an acute hospital in Singapore. Singapore Med J. 2006; 47: 367 – 372.

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