Lt. Col. Elizabeth Rouse, who performed the autopsy on the prisoner known as Dilawar, said his muscles were "crumbling and falling apart."

She testified Tuesday that the injuries could have been caused by repeated knee strikes or by a fist.

Army Pfc. Willie V. Brand, 26, an Ohio reservist, is accused of abusing two prisoners in 2002, both of whom later died.

The defense has said Brand was ill-trained for his duties and was simply following orders. Prosecutors say Brand was never taught or ordered to abuse prisoners.

Several other soldiers charged with mistreating detainees at Bagram airfield in Afghanistan have pleaded guilty or announced their intention to do so.

No officers in charge of training soldiers involved in the abuse cases or those who oversaw operations at the airfield have been charged. Military officials have said the investigation is continuing.