Robert L. Kronisch

Mountain Biking Injuries An Update

AbstractThis article reviews the available literature regarding injuries in off-road bicyclists. Recent progress in injury research has allowed the description of several patterns of injury in this sport. Mountain biking remains popular, particularly among young males, although sales and participation figures have decreased in the last several years. Competition in downhill racing has increased, while crosscountry racing has decreased somewhat in popularity. Recreational riders comprise the largest segment of participants, but little is known about the demographics and injury epidemiology of noncompetitive mountain cyclists.Most mountain bikers participating in surveys reported a history of previous injuries, but prospective studies conducted at mountain bike races have found injury rates of <1%. The most common mechanism of injury involves a forward fall over the handlebars, usually while riding downhill, which can result in direct trauma to the head, torso and upper extremities. Avariety of factors can be associated with this type of fall, including trail surface irregularities, mechanical failures and loss of control. In mountain bike racing the risk of injury may be higher for women than men.Minor injuries such as abrasions and contusions occur frequently, but are usually of little consequence. Fractures usually involve the torso or upper extremities, and shoulder injuries are common. Head and face injuries are not always prevented by current helmet designs. Fatal injuries are rare but have been reported.Improvements in safety equipment, rider training and racecourse design are suggested injury prevention measures. The authors encourage continued research in this sport.

Off-road cycling injuries. An overview.

SummaryOff-road bicycles, commonly called ‘mountain bikes’, have become increasingly popular worldwide since their introduction in the western US in the late 1970s. This popularity is partly because these vehicles can be ridden on a wide variety of terrain which is not accessible to other types of bicycle. Although early versions were rather crude, off-road bicycles today typically include high strength, lightweight frames with a wide array of available suspension and braking systems. Virtually all aspects of the technology continue to evolve, including components and protective equipment. As the popularity of off-road cycling has increased, so too has the interest and level of participation in the competitive aspects of the sport. Currently, 2 organisations — the National Off-Road Bicycle Association (NORBA) and the Union Cycliste Internationale (UCI) — sponsor the major events within the US and around the world.To date, the majority of studies have been descriptive in nature, with data collected via self-report, questionnaire formats. Only 1 prospective study has been reported thus far, which surveyed a major international competition held in the US in 1994. Injury rates calculated on the basis of injuries per ride or event in competitive venues have been reported, ranging from 0.2 to 0.39% compared with 0.30% for recreational participants. Retrospective data collected from recreational and competitive riders indicate that from 20 to 88% of those surveyed reported having sustained an injury during the previous year of participation. The majority of injuries appear to be acute, traumatic episodes involving the extremities, with contusions and abrasions being the most common. In general, the incidence of more severe injuries such as dislocations, fractures and concussions is low. Comparisons between road and off-road cycling events indicate that off-road cyclists sustain more fractures, dislocations and concussions than their road-event counterparts.Future research should incorporate epidemiological methods of data collection to determine the relationships between vehicle design, terrain and safety equipment and riding-related accidents. Further, those engaged in such research should attempt to set a standard definition for injury.

Acute injuries in off-road bicycle racing

A descriptive study was conducted to investigate inju ries sustained at a major off-road bicycling race at Mammoth Mountain, California, July 6 to 10, 1994. A total of 4027 individual starts in five events during the race were reported. Overall, the total number of com petitors in the 5 events was 3624, with some cyclists participating in multiple events. Injuries were consid ered significant if they occurred during competition and prevented the rider from completing the event. Sixteen cyclists had injuries that met these criteria for an over all injury rate of 0.40%. These 16 cyclists had 44 injuries. Abrasions were the most common injury, fol lowed by contusions, lacerations, fractures, and con cussions. The mean injury severity score was 3.0 (range, 1 to 5) with 81.2% of the injuries resulting from cyclists going downhill. Injuries were more severe when the riders were thrown from the bicycles (P = 0.03). We observed different mechanisms of injury in various events, suggesting that the risk factors for sustaining a traumatic injury may vary according to the type of competition involved.

Mechanisms of injury in competitive off-road bicycling.

OBJECTIVE To describe the mechanisms of injury from crashes during competitive off-road bicycling (mountain biking) and to examine the type, location, and severity of the resulting injuries. METHODS We examined and interviewed all bicyclists injured while competing at 7 off-road bicycling events. Information regarding the direction of fall and the presence of a collision or mechanical failure was obtained, and the injury patterns were compared. 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.

Gender differences in acute mountain bike racing injuries.

ObjectiveTo evaluate injury rates and patterns in off-road bicycle racing, and to compare the findings in male and female cyclists. SettingThe study was conducted from 1994–2001 at a large off-road bicycling competition held for 4 days each summer at Mammoth Mountain, California. DesignInjured cyclists were evaluated at the first aid station or at the local hospital. Registration data were used to estimate the number of male and female competitors in each race. ParticipantsCyclists who sustained an injury during a race and were unable to finish the race due to the injury were included in the study. 22 female subjects and 71 male subjects met the inclusion criteria during the 8-year study period. There were a total of 20,769 race participants during the study period. Main Outcome MeasuresInjuries were categorized, and injury rates were calculated. ResultsThe overall injury rate during the study period was 0.77% (22/2,869) for women versus 0.40% (71/17,900) for men (p = 0.01). Fractures were sustained by 45.5% (10/22) of female subjects versus 21.1% (15/71) of male subjects (p = 0.03). Odds ratios indicate that overall, women were 1.94 times more likely than men to sustain an injury and 4.17 times more likely to sustain a fracture. ConclusionsThese data suggest that although participation in this sport is higher among men, the risk of injury is greater for women.

Traumatic Injuries in Off-Road Bicycling

Two hundred sixty-five members of 21 off-road cycling clubs in 12 states completed a four-page questionnaire regarding their riding habits and injury history for the 1992 cycling season. The response rate was 62.4%. Of those surveyed, 85.7% reported injuries that were sustained while mountain biking during the preceding 12 months, with abrasions, contusions, and lacerations being reported most frequently. Injuries were considered significant if the cyclist sought medical attention for the injury and was unable to ride for at least 1 day due to the injury. Sixty injuries met these criteria. Of those, 90% were traumatic in nature, making the incidence of significant traumatic injury 20.4% in this group for the year studied. Fractures were the most common significant traumatic injury reported. The shoulder complex was the most commonly injured anatomic region. Loss of control, high-speed descent, and competitive activity level were identified as variables associated with traumatic injury. Competitive activity level was the only independent risk factor positively associated with traumatic injury, with an adjusted odds ratio of 4.24 (p < 0.0001).

Acute injuries in cross-country and downhill off-road bicycle racing.

This study was conducted to investigate injury patterns at three major off-road bicycle races in the Western United States in 1995. All cyclists forced out of the cross-country (CC) and downhill (DH) competitions due to injury were examined and interviewed. The overall injury rates were 0.49% (20/4074) for the CC and 0.51% (11/2158) for the DH event. In the CC there were 0.37 injured cyclists for every 100 h of racing time versus 4.34 injured cyclists/100 h in the DH (P = 0.01). Injury rates in the CC were higher for women than for men (1.05% vs 0.40%, P = 0.04; 0.75/100 h vs 0.31/100 h, P = 0.01). Injured CC cyclists who fell forward over their handlebars had higher mean injury severity scores (3.0 vs 1.3, P = 0.01) and required more emergency room visits (6/100 vs 1/10, P = 0.02) than cyclists who fell off their bicycles (5/6 vs 5/14, P = 0.05) and were taken to the hospital (4/6 vs 3/14, P = 0.05) more often than men. These data suggest that 1) the risk of being injured during a race is similar in the CC And DH events, 2) the long-term risk may be greater to DH racers than to CC competitors, 3) the severity of injury is greater when a CC cyclists falls forward off the bicycle, and 4) women CC competitors are more likely to fall forward off their bicycles and be injured than men.

How to fit a mountain bike.

Having a mountain bike that fits you well is important not only for comfort but also for helping to prevent injuries. A bike thats the wrong size or poorly adjusted increases your chance of developing an overuse injury. The best way to adjust your bike so that it correctly fits your body is to follow these guidelines with the assistance of someone who understands the relevant anatomy and has experience working with cyclists. It is very difficult to perform some of the measurements on yourself. (These guidelines also apply to fitting a road bike, except where indicated.).