The world of sport has sent messages of support to Michael Schumacher on his 50th birthday as the seven-time Formula One champion continues to recover from a skiing accident in 2013.

#KeepFightingMichael was trending on social media around the world on Thursday morning in support of the most-decorated driver in F1 history, who suffered a traumatic brain injury while holidaying in the French Alps five years ago.

The Ferrari F1 team, where Schumacher earned five titles in 10 seasons, tweeted: "Our champ turns 50 today. We're all with you Michael #KeepFighting."

F1 driver Nico Hulkenberg shared a photo of when he met Schumacher as a young man, writing "Happy 50th birthday, Goat!", a reference to a popular acronym for "greatest of all time".

"Stay strong and keep fighting!!" he added.

Rival F1 teams, like Renault, McLaren and Mercedes, as well as the official accounts for race tracks like Brands Hatch and the Nurburgring, also wished Schumacher well.

The Mercedes team, where Schumacher finished his career, wrote on Twitter: "50 years ago, a star was born. A star who shaped and changed @F1 forever. Who broke records, redefined excellence and helped lay the foundations for our future success.

"We'd like to send our very best wishes to Michael @Schumacher on his 50th birthday. #KeepFighting #Michael50."

Seb Morris, the British 2017 GT Champion, said on Twitter: "Happy birthday @schumacher . Not a day goes by where I don't think about you and your progress. #KeepFightingMichael."

Tributes also extended beyond motor sport.

The German national football team posted a tribute on Twitter wishing Schumacher a happy birthday alongside a picture of the driver visiting his countrymen in training.

In a tweet on the anniversary of the accident, former Arsenal and Germany striker Lukas Podolski simply posted the praying and strong arm emojis to Twitter alongside the hashtag #KeepFightingMichael.

And the official account for Australian football club South Melbourne FC posted a picture of Schumacher in the club kit after a training session.

"Wishing @F1 legend and friend of the club Michael Schumacher​ a Happy 50th Birthday for today," read the caption.

Schumacher's family led the tributes with the release of a "virtual museum" in the form of an app "to remember and celebrate his victories, his records and his jubilation".

And daughter Gina wished her father a happy birthday on Instagram with pictures from his glory days captioned "to the best dad".

The family of the German-born star, often called the greatest driver of all time, asked for continued privacy in a rare statement on Instagram.

"Please understand if we are following Michael's wishes and keeping such a sensitive subject as health, as it has always been, in privacy," it read.

"We say thank you very much for your friendship and wish you a healthy and happy year 2019."