Hip-hop history: Why was there a guy in a wheelchair sitting next to Michael Jackson at the 1990 American Music Awards?

Hip-hop history: Why was there a guy in a wheelchair sitting next to Michael Jackson at the 1990 American Music Awards?
When the cameras panned over to Michael Jackson during the 1990 American Music Awards, there was a guy in a wheelchair sitting next to him. Shane points us to this clip. And why was he there? Who was he?