The most common injury at the Olympics

"In the Winter Games, we have seen serious injuries in higher-velocity sports like alpine skiing and snowboarding events," he said. "In summer, except for cycling, we seldom see serious injuries."

Engebretsen and his colleagues have been collecting data on the daily injuries that have occurred among athletes at the Winter and Summer Olympic Games for about a decade.

During each competition, the researchers examined injury reports completed by all National Olympic Committee medical teams as well as physicians treating athletes in the various on-site medical venues and clinics at the Olympic Village and other Olympic-related venues.

For every Games, the researchers published a study on their findings.

In 2008, about 1,055 injuries were reported among the 10,942 athletes competing in the Summer Olympic Games in Beijing. About 72% of those injuries were incurred while the athlete was competing.

At the 2010 Winter Olympic Games in Vancouver, about 287 injuries occurred among the 2,566 athletes. Those injuries were almost evenly distributed between training and competition: 54% vs. 46%.

In 2012, there were 1,361 injuries among the 10,568 athletes competing at the Summer Olympic Games in London. About 55% of the injuries occurred while the athlete was competing.

In 2014, there were 391 injuries among the 2,780 athletes at the Winter Olympic Games in Sochi, Russia. Only 35% of those injuries were sustained in competition.

In their latest study on the 2014 findings, which was published last year in the British Journal of Sports Medicine, the researchers wrote, "The overall rate of injury in the Sochi Games was similar to those in Beijing 2008, Vancouver 2010 and in London 2012 (12% of all athletes injured in Sochi versus 11% in Vancouver and London, and 10% in Beijing)."

This year, a similar overall rate of injury is expected at the Summer Olympic Games in Rio de Janeiro, despite the many terrible high-profile injuries that have already occurred.

"There are more than 11,000 athletes in Rio. Therefore, one would expect injuries. The serious injuries we have seen so far are also seen in the same sports in World Cups and other major events," Engebretsen said.

However, these more severe injuries are rare, said Dr. Andrew Cosgarea, head team physician for the Johns Hopkins University Department of Athletics and chief of the Division of Sports Medicine at the Johns Hopkins School of Medicine.

"The most common injuries are overuse injuries," Cosgarea said.

Overuse injuries can range from tendinitis to shin splints, for example. Common symptoms include swelling, soreness and pain.

"So when you see athletes try cupping, dry needling, scraping, massage and compression and ice baths, those are all attempts to try to improve healing and address the constant stress on the body as the athlete pushes the limit," Cosgarea added. "An overuse just implies that the amount of stress that the body is seeing in any given period of time is more than it's capable of accepting or dealing with, without having a negative effect on that tissue."

Sometimes, when a more severe injury occurs, it might be the result of a predisposing factor -- such as a stress fracture that occurred during training -- not healing completely or properly, Cosgarea said.

"There are situations where defects in the bone or lingering stress fractures can predispose to that injury," he said. "But virtually every athlete has had some sort of injury or knows someone who has been injured before."

In 2014, the International Olympic Committee collaborated with nine research centers worldwide and asked them to study, develop and implement effective preventive and treatment measures for injuries. Engebretsen and his colleagues also plan to continue to track and study the injuries that occur during Olympic Games in an effort to better innovate ways to prevent injuries.

"We do this to understand the risks to the athletes based, in part on the patterns and mechanisms of injury," Engebretsen said. "When we understand these patterns, how injuries happen, we can suggest and test ways to mitigate the risks."

For the athletes themselves, Cosgarea said, the injuries can be simply the cost of striving for greatness: "They're taking the risk that allows them to give it their best shot and perhaps win that medal and be an Olympic hero."