There are 4 main systems that contribute to our balance. 1. Muscles and Bones: give us structure and creat movement 2. Vision: tells us about our environment 3. Vestibular: tells our body where our head is within space and senses what direction were moving 4. Proprioception: senses where are joints are so we can make adjustments (on uneven ground) These 4 systems have to work together for us to maintain our balance. When 1 system isn't working as well, the other systems have to make up for it. It's important to train all the systems of balance, especially as we get older.