IT'S ONE OF THE MOST COMMON SPORTS INJURIES: TEARING YOUR A-C-L. HEALING CAN TAKE MONTHS. NOW A VIDEO GAME IS HERE TO HELP GET PEOPLE BACK ON THEIR FEET. TONIGHT'S HEALTHCAST EXPLAINS. N-F-L LINEBACKER KENNY PETTWAY IS SPENDING HIS TIME OFF TEACHING KIDS THE INS AND OUTS OF THE GAME. "I love running down the field and playing special teams, period." HIS JOB: TO KEEP THE OTHER TEAM DOWN. BUT LAST YEAR, A TORN A-C-L FORCED HIM DOWN. "On kickoff, I was running down. My foot got stuck in the ground, and at the same time, somebody grabbed my shoulder. It just blew my ACL out." KENNY HAD A CADAVER A-C-L IMPLANTED. NOW, HE'S USING THIS NEW VIDEO GAME-WORKOUT MACHINE TO HELP HIM GET BACK INTO PLAYING SHAPE. "Exercise is not fun especially when you're a pro athlete, and you can't do your thing. You need something to kind of give you a little competition during the exercise and to take your mind off the pain a little bit, too." DIFFERENT GAMES HELP REBUILD THE A-C-L. IN THIS ONE, KENNY HAS TO CONTROL HIS KNEE MUSCLES TO CONTROL THE BLUE BAR. ANOTHER TESTS HIS POWER. ANOTHER -- DURATION. "Like a wet noodle. I'm shaking." BUT WHAT'S IT LIKE COMPARED TO HIS PAST REHAB? "It's more challenging. It's a little bit more fun because you're playing a game and trying to beat your score. At the end, it gives you a graph and matches your scores up from the previous weeks." THIS MACHINE CAN ALSO BE USED FOR HIP AND ANKLE INJURIES. AFTER TWO MONTHS OF USING THE VIDEO GAME, HE'S PROGRESSED TO THIS… ("When I first came here, I was on crutches. Now, I don't need them anymore.") AND SAYS HE'LL BE READY TO GET BACK IN THE GAME THIS FALL. KENNY PETTWAY PLAYED FOR THE JAGUARS AND THE PACKERS BUT WAS JUST RECENTLY RELEASED FROM HIS CONTRACT. HE WANTS TO GET BACK ON THE FIELD AS SOON AS POSSIBLE. HE SAYS BECAUSE OF THIS NEW GAME HIS REHAB WAS SHORTENED BY SEVERAL MONTHS.