The knee is the body’s most poorly designed joint and the one most susceptible to injury. In the U.S. alone, over one million knee surgeries are performed each year.

A knee injury can end a career. So the game plan for all athletes, on all levels, should be not only to train hard but to train smart. Learn how to protect your knees and reduce your risk of injury.

The knee’s vulnerability to injury depends on the strength of its neighboring muscles. A weak gluteus medius, or outer gluteal muscle, increases the chance of a knee injury by a factor of three. This muscle is critical for knee health, because it acts as a steering wheel for the entire leg.

Athletes place a lot of emphasis on building up their quadricep and hamstring muscles, but they often neglect abducting their legs. Like the transverse abdominals, scapulae and rotator cuff, the gluteus medius must be isolated for stability and strength work. Failing to train these muscles inhibits full movement and raises the risk of injury.

During a squat movement, especially a single leg variation, athletes should be closely monitored for inward movement of the knee, which indicates potential weakness in the gluteus medius.

Try the gluteus medias muscle stretch: the Couch Hang.

Couch Hang

• Lie on your side on exercise bench
• Let your top leg hang down in front of your body
• Hold for 30 seconds.
• Perform two sets on each side. When you stand up, you will notice an immediate improvement in balance.

Other strengthening exercises include Straight Leg Side Lifts, Bridges with bent leg on top of bottom leg, Lateral Walks with band around ankles, Single Leg Squats on a decline bench, Side Steps up a stair case, and Lateral Wall Sits. Begin these exercises from the ground up, 30 seconds each, in a circuit, one to three times a week.

Tightness in the adductors weakens the gluteus medius. Get in the habit of performing mobility exercises like foam rolling and static stretching post-activity. Check out several of the best foam rolling exercises and post-workout stretches.