Proprioception -- your body's sense of the position and motion of your joints -- is one of the most significant factors in balance, graceful movement and injury prevention. It allows involuntary reflexes to stabilize and protect you by maintaining posture and balance as you move. This is especially vital for joints like the knee, which is often injured by loss of balance. It may be harder to measure than strength or speed, but studies have shown you can improve proprioception with special exercises.
Balance training is an effective way to improve knee proprioception, whether you are trying to heal from an injury or prevent one. Standing or performing light exercises on an unstable surface, such as an instability dome or wobble board, challenges the stabilizer muscles in the knee, ankles and hips. For example, you can stand on an instability dome with one leg, or stand with both legs and do knee circles and mini-squats. Any movement that makes you work to maintain stability will improve proprioception, and over time this can have large benefits, including injury prevention.
Ditch the Equipment
For the best results, do a little stability training every day, especially to restore balance and mobility after knee injuries. If you don't own instability equipment and don't want to go to the gym every day, there are exercises you can do anywhere and without equipment. First, take off your shoes -- going unshod increases proprioception. Stand on one leg with your knee slight bent, then lift the other knee to hip height. Hold this position for as long as you can, and repeat with the other leg. To make it more difficult, close your eyes.