Wimbledon 2013: Why have there been so many injuries?

As seven players pulled out of Wimbledon on Wednesday, the pessimistic among tennis fans may have feared an injury epidemic was sweeping their sport.

To have so many withdrawals in a single day of a Grand Slam was unprecedented. Two more - French duo Llodra and Paul-Henri Mathieu - followed on Thursday.

But is this an accurate reflection of trends within the professional game, or just a freakish confluence of unrelated incidents?

Across this Wimbledon as a whole, numbers are not yet that startling. Two years ago at the US Open, for example, 17 players were forced to pull out; at Wimbledon in 2008, 13 withdrew with injury.

Neither has the second round of Wimbledon 2013 broken records. Fourteen players withdrew over the opening two rounds of that US Open, 12 in the same period at Wimbledon 2008.

Modern tennis, like any other professional sport, takes a substantial physical toll on its combatants. Quite whether we are seeing anything new this week is another matter.

As Andy Murray said in his BBC Sport column on Thursday: "As athletes, you spend a lot of your time carrying injuries of one sort or another.

"I'd say there are three categories: about 20% of the time your body feels great and you feel nothing; quite a bit of the time you'll have something that might be a bit sore, but it doesn't affect your tennis at all; the rest of the time you can be carrying something that means you have to compensate and make adjustments to your game. Everyone has to deal with it."

Why, then, the seven pull-outs on Wednesday?

Some players - Jo-Wilfried Tsonga and Marin Cilic - came into these Championships carrying exactly the sort of niggles Murray was referring to.

"The challenge for players is to manage those injuries," says Tim Henman, four-time Wimbledon semi-finalist.

"When you come into the Grand Slams you've got to make sure you are 100% fit and healthy. If you don't do that then you are not going to give yourself the best possible chance. That's where the top four lead by example - they are meticulous with their schedule, and I think the others can learn from that.

"Players do risk playing at Grand Slams with niggles. You have to weigh up the options whether you are going to do yourself really long-term damage or whether it is something you can manage.

"Andy was a good example in Paris; he had an issue that was really going to restrict him, so it wasn't worth the risk, and now he is reaping the rewards.

"Just because there have been these injuries this week doesn't mean, for me, players are playing too much. It's more a co-incidence they've all happened together."

Other injury victims this week, fresh from the clay-court season, were in the process of adjusting to the different demands of playing on grass.

"It's easy when we start getting a day like that to think that the world isn't round any more," says former British number one Mark Petchey, here as an analyst for BBC Sport. "It was just a freak day.

"Some of it had to do with the fact that not many people grow up on grass anymore, whereas we perhaps did to some degree.

"Learning to move on it is an art. Small steps are more important, guys have to learn how to slide so well on clay and even on hard courts.

"That means taking a big step and slamming your weight into your outside foot and I think that has contributed to a few people falling in the manner they have. They need to get out wide, taking small steps to keep their balance.

"The biggest thing with grass is the change of movement. We've had a very damp spring and summer and notoriously the courts are slippery in the first few days, and that will have been a contributing factor to injuries. The courts don't seem any different and they look immaculate as they always do. It was just one of those freak days."

Neither do the players involved see any unified underlying factors behind the glut of injuries.

"The other days, other weeks, there were no pull-outs," said Cilic, whose left knee prevented him taking on Frenchman Kenny De Schepper. "Everything just happened today."

John Isner, who managed just two games of his match against Adrian Mannarino of France before retiring, said the injury to his left knee was nothing but chance. "I always serve and land on my left leg, like I have done 20 million times playing this game, and this is the first time I just felt this sharp pain," he said.

Has 21st Century tennis become too physical, the demands placed on its brightest stars too great?

"I wouldn't put it that way," says Cilic, whose height means he often has problems with his knees when dealing with the lower bounce of grass courts.

"In any sport, athletes are driving themselves to be at their limits. There is always a fine limit between overdoing it and being in 100% shape. That's sometimes what we have to deal with during the year.

"You're always trying to do all the things right to prevent those kinds of things, but you can't prevent everything."

Women's second seed Victoria Azarenka was unable to begin her second-round match after falling heavily during her first-round victory over Maria Joao Koehler. But every one of the world's top-10 ranked women's players have made it to Wimbledon, an improvement on the problems that dogged the WTA Tour in the previous decade.

In 2005, for example, ankle and knee injuries meant Serena Williams played only 28 games; Maria Sharapova struggled with a back injury that summer and then suffered with pectoral problems; Kim Clijsters spent time out with wrist and knee injuries, Justine Henin-Hardenne was sidelined by knee and hamstring injuries all year and Jennifer Capriati missed the entire season with a shoulder problem.

Neither does Petchey believe the demands of the men's game have grown more onerous.

"Maybe the physicality of the game has changed a bit and the rallies are a bit longer and the points were a lot shorter back then," he says. "But you can argue that that was a more dynamic movement than what they are going through now, which is more endurance based."

Is the season too long, the number of matches played too great?

"I don't think it's about if it's short or not," says Tsonga, the sixth seed here at Wimbledon. "It's about if we have some time to rest after tournaments because they all follow each other. If you play for nine months, every day, for sure you will get injured.

"I have to play almost every week if I want to keep my ranking and have some opportunity in big tournaments. So I have to play almost every week because I'm not winning, for the moment, huge tournaments."

To cope better with such burdens, almost every player in the world's top echelons now travels with a team designed specifically around their fitness needs. Murray has trainer Jez Green and physio Andy Ireland; Djokovic has trainer Gebhard Phil-Gritsch and physio Miljan Amanovic permanently on hand.

The sport may have got faster, the rallies more intense. But the players are protected and prepared in a way that their predecessors could never have imagined. Neither are their overall schedules as packed as in the past.

"If you look at the year-end totals of games played," says Petchey, "You could argue that someone like John McEnroe played more, because he used to play so much doubles on top of all the singles success he had."