Margera says he was racing his neighbor up a set of stairs ... and promised the guy he could have one of Bam's skateboards if he won -- but, "Somehow I wound up tumbling down the stairs."
Bam explains, "I tackled my neighbor and fell down the stairs horsing around. I’m still in the hospital."
Bam says he's still unsure about the extent of his injuries -- but he may have broken his arm and several ribs.
Knoxville went to his blog this weekend ... and explained why he froze up while speaking at Ryan Dunn's memorial service last week ... saying he tried his best, but "What came out were the mumblings of a man trying his best not to cry."
Knoxville writes, "Here is what I wished I could have told everyone then."
During the painfully honest blog, Johnny explains how much he loved Dunn -- he loved Dunn's "hair trigger laugh reflex ... Dunn was a great listener ... a great friend ... "as loyal as they come."
But midway through the tribute, Knoxville expresses his discontent with Dunn ... saying, "I'm becoming upset now because this isn't right, goddamnit. Ryan, I had to go wake up Madison and tell her you were gone. Do you know how hard that was?!! She loved you so much and I know you loved her, so why, buddy? Rocko will never get to know you like she did, nor will my daughter that is coming in October. I cry a lot about that."
Knoxville -- who refers to Dunn as his "brother" -- closed the post by saying, "I don't know what else to say right now, so I will close with I love you, Ryan. I have a lot of emotions swirling, but I want you to know I love you so very much."
Johnny continued the post saying, "RIP Ryan , I love you buddy."
Knoxville and Dunn famously goofed off in the "Jackass" films together -- and from the sound of the tweet -- it appears they were pretty close.
TMZ also spoke with Jeff Tremaine -- who starred and directed the "Jackass" movies -- who told us, "I feel like I lost a brother. Ryan Dunn was family and we are all deeply devastated."
Wee Man has also tweeted -- "RYAN DUNN-- a super awesome memory was at the J RODY walston & the business show!!! I MISS YOU BUD!! You were always a happy kick-ass dude!!"
Dunn died in a car accident this morning in Pennsylvania -- when his car sped off the road and crashed into the woods. It was "fully engulfed in flames" when police arrived on the scene.
TMZ has learned ... Lacy was busted in Oklahoma on December 14 -- after cops say Lacy was in possession of a controlled substance (weed) and drug paraphernalia (rolling papers).
Lacy was charged with two misdemeanors -- and if convicted, he could spend up to two years in prison and face $2,000 in fines.
Attempts to reach Preston were unsuccessful.
Bam was hanging poolside in L.A. yesterday with a few of his "Jackass" buddies -- when he gave us a look into his busted up melon.
After the peep show, Bam told us he thinks his alleged assailant is in big trouble with the law -- check out the video to get his side of the story.
Bam tells TMZ he flew from West Chester, PA to Los Angeles yesterday so he and the boys could shoot the intro to the movie -- in which they're all supposed to take gnarly shots to the dome in 3-D slow motion.
Bam says his head-shot scene has to be rewritten because he suffered a concussion and internal bleeding on Saturday -- when he was allegedly attacked by a bat-wielding 59-year-old woman.
As for Bam's replacement scene ... it's probably gonna hurt anyway.
If it looks like Knoxville is on a Ferris wheel trying to throw a basketball at a trampoline 60 ft. below so it hits fellow "Jackass" Chris Pontius in the family jewels ... well, then you're right. That's exactly what he's doing.
We're told Knoxville and his sidekick attempted the stunt -- filmed Friday in L.A. -- over 90 times ... without much success.
The two Jackasses have a history of getting testy.
The photos were taken immediately after the incident, as the "Jackass" star was being loaded into an ambulance.
His condition is unknown.
UPDATE: We talked to Steve-O, who says Bam was holed up in the intensive care unit after the incident ... but has already been released from the hospital.
Steve-O also said, "I think he's gonna be okay."
TMZ has learned "Jackass" star Bam Margera has been hospitalized after being attacked by a bat-wielding woman.
Cops tell us ... it happened at 2 AM this morning, outside Bam's bar in West Chester, PA. There was some sort of fight, that ended when the woman allegedly hit Bam in the back of the head with a baseball bat.
The woman was arrested and charged with assault.
Bam was taken to the Chester County Hospital. His condition is unknown.
UPDATE: According to court documents, 59-year-old Elizabeth Ray faces the following five charges: Two counts of simple assault, two counts of recklessly endangering another person and one felony count of aggravated assault.
The "Jackass" star stopped by the dreaded California DMV after appearing in court today with attorney Barry Gerald Sands -- where he proved to a judge he's been 100% sober for 18 months since his arrest in 2008. The judge was so impressed he dismissed the felony drug charge for cocaine possession ... and even took Steve-O's arrest off his record.
But some things never change -- Steve-O tells TMZ he was at the DMV because he lost his wallet after getting naked and donning a wrestling singlet for an upcoming Jackass 3D flick.