The witness in question is John Good, a Florida neighbor who's been pushed into using a cop's "ground and pound" terminology to describe the penultimate battle between Martin and Zimmerman on that fateful night last February. Here's CBS News on his cross-examination:
The struggle moved to the cement pathway, and he said the person in dark clothing straddled the other man in "mixed martial arts position" he later described to police as a "ground and pound." ...
Later, prosecutor Bernie de la Rionda asked whether it was possible a police officer could have used the term "ground and pound" before he did.
"It's possible," Good said.
MORE ON THE TRAYVON MARTIN TRIAL
- My Star Witness Is Black: Rachel Jeantel's Testimony Makes Trayvon a Show Trial
- Why Are There Cameras in the Trayvon Martin Courtroom?
- The Stupidest Things Said on TV About the Trayvon Martin Case
But enough with words. Here's a terrible "ground and pound" as demonstrated by HLN's Jane Velez-Mitchell — terrible in that it borders on dry-humping:
Because you endured some of that, we've also turned Velez Mitchell's reenactment into a GIF:
Anyways, here's one actual "ground and pound" that shows the intricacies of the move, and actually illustrates what Good was talking about — or at least what the defense wants him to talk about to make Martin look like a dominant pro fighter:
As pointed out by Dennis Kang, the instructor in the video above, the fighter on top has the advantage, but the fighter on the receiving end of a "ground and pound" isn't exactly powerless. He notes that the person on the bottom — say, George Zimmerman, alleged murderer — is still able to block punches. The person on top — say, a kid with a bottle of iced tea — can get fatigued.
Ultimately, of course, MMA moves don't prove or disprove Zimmerman's claim of self-defense. Good himself said he could only see downward movements, which doesn't confirm the defense's narrative that Martin was bashing Zimmerman's head against the sidewalk and using the pavement as a weapon. And, of course, the UFC is much different than fighting for your life.
September Mcfield : Graphicdesigner 
Dante Schaumann : Cashier 
Doyle Piggott : Schoolmistress 
Wilmer Romeiro : Botanist 
Alvin Fermin : Barrister 
Colby Gahm : Doctor