The term proprioception refers to a sense of joint position. Proprioception training is highly common in rehabilitation of injured athletes, but it can just as easily be used to prevent injury. Even a strong ankle can sprain when running on uneven ground if the runner hasn’t trained the neuromuscular system to react appropriately. Slight deviations in terrain require slight adjustments of balance to avoid injury.
So you’re not a runner. Why should you care about balance? Well, for starters, it’s the basic skill needed in practically every sport. From soccer to tennis to rock climbing, changing your center of gravity to match your moves is the key to efficiency in sport. The technical term is agility. Agility is what allows us to move gracefully, wasting little motion. It allows our joints to move through the full range of motion smoothly and confidently. While the start of hiking season might require that your entire attention remain focused on the trail to avoid falling, after several weeks for hiking, you may notice that you are more confident in your ability to adjust to the terrain by foot feel alone, and you need to pay less attention to the trail. In this way you increase your kinesthetic coordination, and in turn your balance improves.
Kinesthetic awareness, or the ability to know where your body parts are in 3-dimensional space, is required for every movement we make. So it's not surprising that balance can be learned, challenged, and improved. Balance training aids come in a variety of forms, although you can just as easily improve your balance with little or none of the fancy stuff. We can train our bodies to improve the proprioception within the muscles, just by creating balance challenges for ourselves.
Here's an easy exercise you can try now: The One leg Squat and Reach. Stand on one foot. Next, reach forward and touch the ground or a small object in front of you and stand up straight again. You can also do partner exercise -- use a medicine ball and play a game of catch while balancing on one foot.