ST. LOUIS -- Rams quarterback Kurt Warner missed most of practice Thursday because of cramps in his rib cage.
Warner, the NFL's MVP, was treated for bruised ribs earlier in the day with electrical stimulution. Coach Mike Martz said the stimulation might have caused the cramps.
"He's got a lot of spasms in there, so when that happens you can hurt your back because you overcompensate when you throw the ball," Martz said after practice. "He was fine yesterday and he'll be fine tomorrow."
Warner injured his ribs in the Rams' 45-17 playoff victory over the Green Bay Packers. He's been dogged by physical problems in recent weeks, including bruised vocal cords in the regular-season finale against the Falcons.
Backup Jamie Martin took all the snaps in practice Thursday leading to Sunday's NFC championship game with Philadelphia.
"He did a nice job," Martz said. "Jamie is ready to go. He's got a nice grasp for what we're doing."