Mechanisms of Injury in Competitive Off-Road Bicycling☆

Publisher Website
Google Scholar
Abstract
Results There were 97 injured riders, with a mean age of 28.3 years. Most victims were male (74%), and all cyclists wore helmets. Most injuries were minor and involved the extremities (70.5%). Injuries sustained from falling forward over the handlebars occurred more often than from falling to the side (65% vs 25%), tended to lead to injuries that were more severe (mean injury severity score [ISS] = 3.4 vs 1.7, P < .05), and produced more head and neck injuries (56% vs 8%, P < .05). Falls to the side generally led to a lower extremity injury (88% vs 57%, P < .05). Riders who were involved in collisions had injuries that were similar in severity and location to those of riders who had no collision. Conclusions These findings suggest that off-road bicyclists whose mechanism of injury involves falling forward over the handlebars are at risk for more severe injury, especially to the head and neck. Key words off-road bicycling mechanism of injury trauma injury Introduction Off-road bicycling, also known as mountain biking, has enjoyed increasing popularity as well as international attention since its beginnings in the 1970s. Today, mountain bikes, which are intended for use in any terrain, continue to be the volume leader in the bicycle industry, whose statistics show 55% of bikes sold in 1997 were all-terrain bicycles. 1 In spite of this dominance, information available on injury risks from off-road bicycling is relatively sparse and comes from the few epidemiological studies done recently. The surveys of recreational cyclists are consistent in their findings that off-road cycling often leads to injuries (51% to 86% within the past year), but most injuries are minor. 2 , 3 Other research focused on competitive cyclists 4 , 5 and also demonstrated a preponderance of minor injuries. These studies were descriptive, focused mainly on the injuries themselves, and offered little information about the mechanism of injury. The limitation with some of these studies is that they are retrospective in nature and depend on victim recall. Also, they include injuries of all types, most of which are minor, requiring no professional evaluation or time off from work or school. Kronisch et al 5 , 6 studied competitive off-road cyclists in a prospective manner and described injury rates and patterns and mechanism of injury. The data suggested a possible correlation between injury mechanism and injury severity. This study was done to evaluate more victims of mountain bike racing in an effort to better describe the relationship between injury mechanism and injury type, location, and severity. Methods This investigation is an extension of the study begun in 1994 and now consists of a larger sample population. The methods have been described in detail previously 6 and are summarized here. Beginning in 1994, we attended a total of 7 mountain bike racing events organized by the National Off-Road Bicycling Association (NORBA)—Vail and Mount Spokane in 1995 as well as Mammoth Mountain each summer from 1994 to 1998. Events included the following: 1) downhill racing, a high-speed individual time trial; 2) cross-country, an endurance event with uphill and downhill riding; 3) dual slalom, a short downhill course consisting of multiple turns, gates, and jumps in which 2 riders maneuver side by side; and 4) observed trials, an obstacle course that tests the cyclist's balancing skills. Participants included amateur as well as professional cyclists, and all were required to wear helmets. All riders who sustained an injury severe enough to prevent them from continuing their respective race were eligible. Each race event provided emergency medical care, and one or both of the authors were available to evaluate the victims who fit the inclusion criteria. All diagnoses were provided by the evaluating physician at the scene or by the physician at the emergency department of local hospitals if victims required more sophisticated care. The abbreviated injury score 7 was determined for each diagnosis, and the injury severity score (ISS) 8 , 9 was then calculated. Each victim was also asked to answer a standardized questionnaire that elicited information regarding demographics and mechanism of injury, including direction of fall, presence of collision, and mechanical failure. This information was provided by eye witnesses of the crash for racers who could not recall the event. All victims gave written consent to participate in this study, and the protocol was approved by the Institutional Review Board at San Jose State University. All information obtained was entered into a computer program (MS Excel) and tabulated. We used the statistical program Primer of Biostatistics for calculation of the P value from chi-square testing or Mann-Whitney rank sum where appropriate. Results We evaluated 97 victims whose ages ranged from 15 to 59 with a mean of 28.3 years. Most victims were male ( n = 72). The majority of crashes occurred while riding downhill (85.6%), and the most common direction of fall was forward (64.9%). The cause of the crash varied widely, although most of the time, the victim cited loss of control as the cause. Collisions and mechanical failure were less common and occurred 23.7% and 15.5% of the time, respectively. These results are summarized in Table 1 . A total of 190 injuries were sustained by all victims, and these are shown in Table 2 . The majority of injuries were minor, consisting of contusions, abrasions, and lacerations to soft tissue. Most injuries occurred to the extremities, with a nearly equal distribution to the upper and lower limbs (34.2% vs 36.3%), but the incidence of fracture or dislocation was higher in the upper extremities (12.1% vs 2.1%). Incidence of injury to the head, neck, and face was significant and included 20.5% of all injuries. Forty-five riders (46.4%) were treated onsite, and, of the 52 injured cyclists who were sent to local hospitals, 3 required hospital admission. The ISS...

This publication has 0 references indexed in Scilit: