FDJ rider William Bonnet of France receives medical help as he sits on the ground after a fall during the 159,5 km (99 miles) third stage of the 102nd Tour de France cycling race from Anvers to Huy, Belgium, July 6, 2015. REUTERS/Eric Gaillard 

Novak Djokovic from Serbia falls during his men's singles match against Gilles Simon from France at the Wimbledon Tennis Championships, in London June 27, 2014. REUTERS/Stefan Wermuth 

The bull Smoke Show goes after Mike Lee of Fort Worth, Texas after he got bucked off in the Bull Riding event during Championship Sunday at the finals of the Calgary Stampede rodeo in Calgary, Alberta, July 12, 2015. REUTERS/Todd Korol 

Lotto-Jumbo rider Laurens ten Dam of the Netherlands lies on the ground after a fall during the 159,5 km (99 miles) third stage of the 102nd Tour de France cycling race from Anvers to Huy, Belgium, July 6, 2015. REUTERS/Benoit Tessier 

Pakistan's Ahmed Shehzad (top) collides with Sri Lanka's Kaushal Silva as he tries to run back to the wicket during the third day of their second test cricket match in Colombo June 27, 2015. REUTERS/Dinuka Liyanawatte 

Rob Horne (R) from the New South Wales Waratahs scores a try as he is tackled by Waisake Haholo from New Zealand's Highlanders during their Super Rugby semi-final match at the Sydney Football Stadium, Australia, June 27, 2015. REUTERS/David Gray 

Serena Williams of the U.S. slips during her women's singles tennis match against Anna Tatishvili of the U.S. at the Wimbledon Tennis Championships, in London June 24, 2014. REUTERS/Suzanne Plunkett 

Horse Racing - Royal Ascot - Ascot Racecourse - 17/6/15Jimmy Fortune (3rd L) on Spark Plug falls during the 17:00 Royal Hunt Cup Action Images via Reuters / Matthew Childs 

Tennis - Aegon Championships - Queens Club, London - 20/6/15Serbia's Viktor Troicki after sustaining an injury during his semi final match Action Images via Reuters / Paul Childs 

Honda Moto3 rider Efren Vazquez of Spain crashes during the race at the TT Assen Grand Prix at Assen, Netherlands June 27, 2015. REUTERS/Ronald Fleurbaaij 

Winnipeg Blue Bombers' Chris Randle (8) and Montreal Alouettes' Tyrell Sutton (20) crash into a broadcaster during CFL action in Winnipeg, Manitoba July 10, 2015. REUTERS/Trevor Hagan 

Chile's Eduardo Vargas gets a kick in the face from Argentina's Nicolas Otamendi during their Copa America 2015 final soccer match at the National Stadium in Santiago, Chile, July 4, 2015. REUTERS/Jorge Adorno 

A steer jumps over a fallen runner as two Jandilla fighting bulls follow behind at the Mercaderes curve during the first running of the bulls of the San Fermin festival in Pamplona, northern Spain, July 7, 2015. Two runners were gored in the run that lasted 2 minutes and 23 seconds, according to local media. REUTERS/Susana Vera