Bicycle injuries in the US have become more severe and there has been a marked increase in chest and stomach injuries.

Moreover, despite greater public awareness, helmet use has not increased and head injury rates have not fallen.

There is a paucity of studies looking specifically at bicycle injuries, lead researcher Dr. Jeffry Kashuk, from the University of Colorado, Denver, told Reuters Health. In the last several years, greater environmental awareness, economic downturns, an emphasis on fitness, and other factors have fueled greater bicycle use in the US.

The severity of injuries and time spent in hospitalized for bicycle injuries tended to increase in the past decade, according to the findings he presented Tuesday at the American College of Surgeons annual meeting in Chicago. The number of chest injuries rose by 15 percent, while abdominal injuries increased threefold over the last 5 years.

The findings stem from a study of 329 bicycle injuries treated at the Rocky Mountain Regional Trauma Center at Denver Health Medical Center from 1996 to 2006.

Emergency room documentation of helmet use improved during the study period, yet actual use did not change significantly, the researchers found. Roughly one-third of patients studied had a significant head injury.

The rise in injury severity likely reflects an increased rate of motor vehicle associated injuries, which might suggest, along with a trend toward older age, that the injuries occurred in commuters more frequently than the past, as opposed to recreational riders, Kashuk said.

The findings, Kashuk believes, could have important implications for cycling infrastructure in the US.

Although the public is very enthusiastic about bicycle use as a means of transportation, we think that infrastructure has lagged behind in the US, he explained. The government is pushing bike days, and rebates for bike use. Communities are putting in bicycle kiosks. However, there is only limited data to show that we have bikeways to support this increase in bike use.