Think it's your garage door opener opening and closing your door???? Think again........Counterbalance springs are how your door is actually lifted and closed. It is not the opener that actually lifts and closes your door. That just provides the push to get the door moving. It's actually the springs, which are wound tightly when your door is closed. As the door moves up, the springs unwind, which provide the force necessary to lift the door. As the door closes, the weight of the door actually winds the springs back up until it closes completely. At this point the springs have their full tension again.  These springs are normally exposed and when they are under full tension, can be extremely dangerous.