Tearing your ACL is one of the most common sports injuries. Healing can take months, but a video game is helping people get back on their feet.

NFL linebacker Kenny Pettway is spending his time off teaching kids the ins and outs of the game. But last year, a torn ACL 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," Pettway said.

Pettway had a cacaver ACL implanted. Now he's using a 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," said Russell M. Paine, director of rehabilitation at Memorial Hermann Sports Medicine Institute in Houston, Texas.

Different games help rebuilt the ACL. In one game, Pettway has to control his knee muscles to control the blue bar. Another tests his power and another tests his duration. But what is 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," Pettway said.

The machine can also be used for hip and ankle injuries.

After two months of using the video game, he no longer needs crutches and said the video game shortened his rehab by several months.

Additional Information About ACL Tears

WHAT IS YOUR ACL? The anterior cruciate ligament, or ACL, is one of the four major knee ligaments. The ACL is critical to knee stability. It prevents excessive motion of the knee joint.

ACL INJURIES: According to the Mayo Clinic, injuries to the ACL are among the most common of all sports-related knee injuries. Up to 200,000 people sustain a ruptured or torn ACL in the United States each year. The ACL becomes torn when it's stretched beyond its normal range of elasticity. Most often, ACL tears occur when pivoting or landing from a jump.

The knee gives out from under the athlete when the ACL is torn. Wearing cleats during aggressive cutting or pivoting activities may increase the risk of ACL injuries. The injury generally occurs during exercise or sports. Women suffer from ACL injuries more than men do. The exact reason is unclear, but some suspect it may be due to differences in anatomy, hormones or strength.

DIAGNOSING AN ACL INJURY: Doctors will typically diagnose an ACL tear by asking about how the injury occurred, examining a patient's knee and possibly conducting an MRI scan.

Some common tests doctors may use during an exam include the Lachman test, where patients lie on their backs with their knees bent at a 30-degree angle. The doctor gently moves their lower leg forward at the knee. If their leg moves freely without reaching a firm endpoint, they've torn their ACL.

Another test, known as the pivot shift test, involves extending the knee and rotating a patient's foot inward while applying pressure to the outside of the knee and slowly bending it. The doctor is checking for signs of instability indicated by a shifting of the shinbone or the thighbone.

TREATMENT OPTIONS: ACL tears do not always require surgery. There are several important factors to consider before undergoing surgery. If you don't participate in sports that require a functional ACL, and you don't have an unstable knee, experts say you may not need surgery. There is also some debate about how to treat a partial ACL tear.

Some believe if the ACL is not completely torn, surgery may not be necessary. Typical surgery for an ACL tear involves reconstruction using another tendon or ligament to substitute for the torn ligament. Risks include infection, persistent instability and pain, stiffness and difficulty returning to your previous level of activity.