Similar to the systems in your car, problems with your movement system are much easier to deal with if they're caught and treated early. This prevents small issues from becoming larger ones. For example, if you have a little bit of weakness, and balance that's not quite up to par, improving those early could prevent a sprained ankle, or a fall and a broken wrist.
An annual movement screen from your physical therapist can find small issues that you may not have noticed with your strength, balance, flexibility, or coordination. Many of these minor issues can be fixed with a few exercises at home, or with just a few visits.