Bam Margera's fall at a skate park -- which has his wrist currently in a cast -- was painfully and very clearly captured on video newly obtained by TMZ ... and just watching the wipeout is gonna make ya go ... ouch!!!
Bam's tumble went down at the Hobbit Skate Park in Delray Beach, FL ... as you can see, the trick he tried to land didn't work out as planned, slamming him to the ground, right wrist first.
The "Jackass" star tells us it was a trick he hadn't tried in over a year, and it ended with his arm bending backward and bones nearly breaking his skin.
As we reported, Bam just completed 1 year of alcohol and drug treatment, so he's biting the bullet and refusing all painkillers as he recovers from the broken wrist.
Bam says he was in an AA meeting across the street from the skate park and hopped on his board during a 30-minute break ... and the rest, as they say, is disastrous history.