As more older Americans take up motorcycling -- or return to it after a decades-long hiatus -- one thing is becoming clearer to emergency room physicians: When graying riders go down, they go down hard.
A Brown University study published Wednesday in the journal Injury Prevention, found that bikers age 60 and over were 2 1/2 times more likely to wind up in an emergency room with severe injuries than were riders in their 20s and 30s.
Middle-aged riders fared somewhat better, but were still 66% more likely to sustain serious injury than were younger bikers.
"There are always some risks involved with motorcycles," said lead author Tracy Jackson, a doctoral student of epidemiology at Brown's Public Health Program. "But there may be some physical factors that make older riders more prone to being in an accident, or more prone to injury."
Among other findings, authors reported that older and middle-aged adults were more likely to suffer internal organ injuries, most commonly brain injuries. Younger riders, meanwhile, were more likely than older riders to suffer non-serious injuries such as contusions, abrasions, strains or sprains.
Of all injuries, bone fractures were the most common for riders. However, older and middle-aged adults suffered a high proportion of upper-trunk fractures, while younger riders suffered more arm breaks.
"The greater severity of injuries among older adults may be due to the physiological changes that occur as the body ages," the authors wrote. "Bone strength decreases, subcutaneous and visceral fat distribution may change, and there is a decrease in the elasticity of the chest wall. ... Other factors such as delayed reaction time, altered balance and worsening vision may also make older adults more prone to getting into crashes," the authors wrote.
Today, about a quarter of all U.S. motorcycle riders are age 50 or older -- a segment of the riding population that has more than doubled since 1990. This graying group of riders has not only become a focus of motorcycle retailers, it's been studied by public health officials.
Previous regional studies have shown that injuries among riders who were 65 or older increased 87% between 2001 and 2007, while fatalities in that same group increased 145%.
This most recent study is different, however, because it examined specific types of non-fatal injuries between 2001 and 2007, and was based on national emergency room reporting statistics.
Dr. Flash Gordon, a Bay Area physician and motorcyclist who has written magazine columns about motorcycle injuries but was not involved in the Brown report, said he thought the study had "some problems."
Specifically, authors were unable to determine how many people in each age group were riding each year, and were therefore unable to determine if the jump in injuries was due to an increase in the rate of crashes among older riders, or if it was simply due to an increase in the number of older motorcyclists on the road.
"The main thing is comparing not the number of injuries, but the number of injuries per mile, or injuries per rider." Gordon said.
Gordon noted that the severity of injuries suffered by older riders may be due to the fact that they often ride bigger, faster bikes. Also, he said that they might lack less severe injuries such as abrasions because they were better protected.
"The reason abrasions are probably lower in older people is that we've got better gear, and so we don't lose our skin," Gordon said.
The Brown study examined about 1.5 million motorcycle accidents. Researchers, however, did not have data on helmet use, the size of motorcycle involved or specific circumstances of each crash.
Overall, they authors found that older riders had a 35% hospitalization rate, while middle-aged riders had a rate of 25%. Young riders had a rate of 15%.
"The highest rates of hospitalization were for injuries to the head/neck, upper trunk and lower trunk, with older adults being hospitalized approximately half the time they sustained injuries to these sites," the authors wrote.
They suggested two ways of addressing the injury trend among older riders: special courses or training for aging riders and the use of protective chest gear.
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