Men are more likely to strain a hamstring playing college soccer than women, according to a new analysis of National Collegiate Athletic Association (NCAA) injury records.
The findings also suggest that games - as compared to practices - and preseason training are the riskiest times for hamstring tears.
Hamstrings are the group of muscles behind the thigh. When the muscle is stretched too far or when too much force is put on it, muscle fibers can tear. Depending on the severity of the strain, hamstring injuries are treated with anything from a few days of icing and rest to muscle-repairing surgery.
"In terms of the muscle mechanics, I don't know if there is any gender difference there," Bing Yu, from the physical therapy division at the University of North Carolina at Chapel Hill, told Reuters Health.
"But I know that probably females are more flexible. That means that during the same movement, the male may have a higher (chance of) muscle strain," said Yu, who has studied hamstring injuries but wasn't involved in the new research.
It's also possible, he added, that men's greater muscle strength and longer range of motion may put them at higher risk for hamstring injuries in certain soccer scenarios - though so far, there have been no data to back up that theory.
For the new study, Kevin Cross from the UVA-HealthSouth Sports Medicine and Rehabilitation Center in Charlottesville, Virginia, and his colleagues collected information on hamstring tears among soccer players in the NCAA's injury database, which covers a fraction of Division I, II and II schools.
Between the 2004 and 2009 seasons, there were 519 hamstring strains recorded in the database - equal to one injury for every 2,100 games and practices played by a single athlete. That means each team could expect about one of those injuries per season.
Male soccer players were 64 percent more likely to strain their hamstring than female student-athletes, according to the findings published in the American Journal of Sports Medicine. They were also more likely to re-injure an old strained hamstring during play.
There's not much research on the best way to prevent hamstring injuries, according to Yu. Cross said the current focus is on improving cardiovascular fitness to prevent fatigue, since athletes are more likely to get injured when they're overly tired.
"Both sexes have a higher incidence rate of hamstring strains during the preseason compared to in season and during games compared to practices. Those are both times that are higher-intensity activities," Cross told Reuters Health.
"The biggest part is appropriate training with regard to cardiovascular and general conditioning training," he said. "That seems to be the biggest factor going forward."