Active commuting by bicycle: health benefits, injuries and the impact of improving infrastructure

Introduction: As bicycling continue to gain popularity, the number of bicycle related injuries increase. Bicyclist are vulnerable road users; therefore, we want to identify risk factors for serious bicycle injury. Material and methods: A comprehensive search of PubMed was performed. Only studies based on hospital reported data with Abbreviated Injury Score from centres in Europe, North-America and Oceania, published between 2010 and 2020, were included. Results: Eleven studies were identified, covering a total of 228 140 injured bicyclists. Results regarding patient characteristics and crash characteristics were extracted. Males were more likely to sustain bicycle trauma than females, 60-85%. Single bicycle crash was the mechanism behind 52-81% of all bicycle trauma, while 19-42% were due to collisions with motorized vehicles and 3-18% were due to collision with another bicycle. The highest relative risk of sustaining a bicycle injury was during the early morning darkness. Fracture of the upper extremity was the most commonly occurring injury. The use of alcohol before injury was seen in 6-33%. Alcohol intoxication was associated with more head injuries, not wearing a helmet, less collisions with motorized vehicles and more severe injuries. The use of bicycle helmets was associated with less head and face injuries, but more injuries to the extremities and especially to the upper extremity. Conclusion: Risk factors for bicycle trauma were bicycling in the dark, alcohol intoxication, not wearing a helmet, a lack of bicycle friendly infrastructure and non-existent measures for traffic calming. The use of wrist guards for preventing upper extremity fractures should be studied. To mitigate the high risk of injuries associated with bicycling these areas should be addressed by both politicians and bicycling associations alike