The cause of Oakland Raiders wide receiver Antonio Brown's foot injury has been revealed: because he used improper foot protection at a French cryotherapy clinic in July, he's developed severe frostbite, which has kept him out of Raiders training camp since July 30. Summer frostbite isn't an unprecedented reason for a player to miss time -- it famously happened to Rickey Henderson once, after he fell asleep on an ice pack -- but it's certainly not something anyone expected to happen to one of the best receivers in the game.

Brown now joins a bizarre club: athletes who were injured in extremely non-traditional ways. From off-field accidents to celebrations gone wrong, here's a list of the strangest ways players have missed time over the past 20 years.

BILL GRAMATICA

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While playing for the Cardinals in 2001, Gramatica hit a routine field goal to put his team up 3-0 in the first quarter of a mid-December matchup against the Giants. He jumped up in celebration, landed awkwardly, and tore his ACL. "I couldn't tell you right now what I'm going to do," Gramatica said about his celebrations a few months later, "but I know it's not going to be jumping around.''

CHRIS HANSON

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Looking to fire up his team, Jaguars coach Jack del Rio brought an axe and an oak stump into the locker room to remind the squad to "keep choppin' wood." Jaguars punter Chris Hanson accidentally gashed himself while wielding the axe, and he missed the remainder of the 2003 season as a result.

SAMMY SOSA

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Sammy Sosa hit 35 home runs in 2004, but the moment most people will remember from that season was when he strained his back from sneezing too hard.

CLINT BARMES

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Barmes was hitting .329 in a breakout 2005 for the Rockies when the unthinkable happened: He fell and broke his collarbone while carrying a package of deer meat given to him by Todd Helton. Barmes would miss three months and finish the season at .289.

MIKHAIL YOUZHNY

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At the 2008 Miami Masters, Youzhny hit a return against Nicolas Almagro into the net. He responded by smashing his forehead with his racket three times, drawing blood. The truly odd thing? Youzhny ended up winning the match.

BRANDON INGE

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In 2008, Tigers catcher Brandon Inge was adjusting a pillow behind his 3-year-old son's head when he somehow pulled an oblique muscle and landed on the 15-day injured list.

KENDRYS MORALES

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Morales hit a walkoff grand slam against the Mariners in May 2010. When he reached home plate, he jumped in the middle of his teammates in celebration ... and broke his lower left leg when he landed. Morales would miss the remainder of the season.

DUSTIN PENNER

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Kings forward Dustin Penner's wife's pancakes must be delicious, because he suffered back spasms while eating them back in 2012. Fortunately, he only ended up missing a single game.