The risk of serious injury, disability and death is shockingly high among child jockeys in camel races in Gulf countries, a report shows.
The sport using child riders has been banned in many countries
Researchers in Qatar looked at 275 boys, many younger than nine and some as young as five, treated for camel racing injuries at a local hospital.
Seventeen of the boys treated between 1992 and 2003 were left with permanent disabilities and three died.
The findings appear in the Clinical Journal of Sport Medicine.
Although the sport using child riders, many of them trafficked from South Asia, has been banned in many countries, including Qatar since 2005, experts fear many children continue to be at risk.
If reports are accurate, at least 16,000 camels race at the 17 official tracks in the United Arab Emirates.
Fatalities are also likely to be higher than reported because jockeys who died at the scene of the accident would not have been taken to hospital, said the researchers.
Mature camels can be 2 metres high at the shoulder, weigh more than 680kg and run at speeds of up to 35-40 kilometres per hour during a race, which experts say goes some way to explain why such serious injuries can occur.
Dr Abdulbari Bener and colleagues of the University of Qatar found 40% of the injuries the looked at were severe enough to require hospitalisation, with an average hospital stay of six days.
Most were injuries to the arms, legs and head and were caused by falls. The most severe occurred when the camel fell down on top of the thrown rider.
Many of the injured boys had been trafficked from poor countries to serve as camel jockeys - 91% from Sudan.
Before a race, the child riders may go without food for a week, not as punishment but to keep their weight down, meaning they may also be malnourished, Dr Bener and colleagues told the journal.
In an editorial in the same journal, Drs Dennis and Caroline Caine of Western Washington University said: "It is heart-wrenching to imagine a child as young as four or five...perched or strapped on top of a camel as the animal races up to 35 to 40 kilometres per hour.
"By contrast, children four to five years old in Western culture are still learning to ride a bicycle.
"[This] work is extremely important in raising the level of awareness and concern regarding both the frequency and severity of camel racing injuries among children."