Michael Jackson (search) sought medical attention after his trial as he tried to recover from a back injury and dehydration, his lead attorney said Friday.

"This really took a toll on him," attorney Thomas Mesereau Jr. (search) said in a telephone interview. "My understanding is he checked in. Nobody knew about it."

Jackson was acquitted of molestation and conspiracy charges last month in Santa Maria.

The pop star's representatives said he was plagued by back troubles throughout the trial, beginning with a fall that resulted in a trip to an emergency room in March. The judge ordered him back to court, and he arrived wearing pajama bottoms and a T-shirt, walking stiffly.

Reporters staked out a hospital where Jackson made at least two visits during jury deliberations in June, but the post-trial visit apparently escaped their attention.

Jackson's spokeswoman, Raymone K. Bain (search), said at the time of the visits that they were related to the back injury. She later parted ways with the singer.