Cycling is often considered a leisurely activity with minimal potential for severe or chronic injury. Acute head and spinal trauma can be devastating and can predominantly contribute to all-cause mortality in injuries attributed to cycling. Chronic overuse injuries primarily affecting the ulnar, median, and pudendal nerves are also a cause of significant morbidity for the cyclist.
Bicycling is one of the most popular means of transportation, recreation, fitness, and sport among millions of people of all ages. The bicycle has undergone extensive refinements since its initial beginnings as the velocipede in 1817 by Karl von Drais, remaining a readily available form of aerobic nonimpact exercise with established beneficial cardiovascular effects. Bicycling also continues to be a popular means of city transport, especially within Asian and European countries. Commercial interests, such as the postal service and law enforcement, continue to use cycling for transportation. Additionally, in the past, bicycles were an effective vehicle for mobilizing soldiers and supplies to combat zones during World Wars I and II.
Cycling was part of the inaugural first modern Olympic Games in 1896. Since this time, the International Olympic Committee has recognized the popularity of various forms of cycling and included mountain biking in the 1996 games in Atlanta with plans to incorporate bicycle motocross (BMX) in the Olympic Games. Bicycle sales have steadily increased in each decade, with mountain bikes currently accounting for 62% of new bicycle sales in the United States. The increasing attractiveness is not limited to the adult population, however. In 1994, the Centers for Disease Control and Prevention estimated that 73% of children aged 5 to 14 years ride bicycles.
Cycling is not generally considered a high-risk activity. Given the increased number of people riding bicycles and the development of “extreme forms” of the activity, such as mountain biking, however, there has been a continued increase in injury incidence. Generally, bike-related injuries can be classified into acute physical trauma or chronic overuse patterns. The annual incidence of bicycle deaths has been reported as 900, with 23,000 hospital admissions, 580,000 emergency department visits, and greater than 1.2 million physician consults per year.
Bicycle crashes rank second only to riding animals as a sports- or recreation-associated cause of serious injury. Although injuries to mountain bikers of all ages account for only 3.7% of bike injuries overall, up to 51% of recreational and 85% of competitive mountain bikers sustain injuries each year. The peak incidence of bike-related injuries and fatalities is within the group aged 9 to 15 years, whereas 20- to 39-year-old riders comprise the group incurring the most mountain bike injuries. Mortality and morbidity rates attributable to bicycle accidents remain highest in older individuals, male cyclists, and cyclists involved in collisions with motor vehicles.
Most bicycle-related injuries involve superficial trauma, such as abrasions, contusions, and lacerations. Significant trauma to the upper and lower extremities and to the head, face, abdomen, and thorax are also commonly seen. Neurologic involvement, unfortunately, may represent a large proportion of the more severe injury patterns. Head injuries, in particular, often involve collision with a motor vehicle and are responsible for more than 60% of all bicycle-related deaths and most long-term disabilities.