Old Age and Motorcycles Are a Dangerous Mix If you're over 40 and planning to hop on a motorcycle, take care. Compared with younger riders, the odds of being seriously injured are high. That is the message of a new study, published this week in the journal Injury Prevention, which found that older bikers are three times as likely to be severely injured in a crash as younger riders. The percentage of older bikers on the road is quickly rising, and their involvement in accidents is a growing concern. Nationwide, from 1990 to 2003, the number of motorcyclists over 50 rose from roughly 1 in 10 to about 1 in 4. At the same time, the average age of riders involved in motorcycle crashes has also been climbing. Injury rates among those 65 and older jumped 145 percent from 2000 to 2006 alone. Because of the increase in motorcycle ridership among older Americans, the researchers, led by Tracy L. Jackson, a graduate student in the epidemiology department at Brown University, wanted a closer look at their injury patterns. So she and her colleagues combed through a federal database of motorcycle crashes that were serious enough to require emergency medical care. That yielded about 1.5 million cases involving motorcyclists 20 or older from 2001 to 2008. The researchers then split them into groups: riders in their 20s and 30s, another group between 40 and 59, and those 60 and older. Over all, the study found that injury rates for all three groups were on the rise. But the rise was steepest for the oldest riders. Compared with the youngest motorcyclists, those 60 and older were two and a half times as likely to end up with serious injuries, and three times as likely to be admitted to a hospital. The riders who were middle age were twice as likely as their younger counterparts to be hospitalized. For older riders, the consequences of a collision were also especially alarming. Older and middle-age bikers were more likely to sustain fractures and dislocations, and they had a far greater chance of ending up with injuries to internal organs, including brain damage. The researchers speculated that it was very likely that a number of factors played a role in older riders' higher injury rates. For one, declines in vision and reaction time may make older riders more prone to mistakes that result in collisions. Another theory is that older riders tend to ride bigger bikes, "which may be more likely to roll or turn over," Ms. Jackson said. Then there is the greater fragility that comes with age. Older riders may be involved in the same types of accidents as younger riders, Ms. Jackson said, but in some cases, a collision that a 20-year-old might walk away from could send a 65-year-old to the hospital. "Your bones become more brittle, and you lose muscle mass as you get older," she said. It could just be a matter of aging and the body being less durable.