The second type of vibration is low frequency. It's just hard to keep the camera level if your body is moving up and down. Getting rid of this type of vibration is probably best accomplished with a lot of practice and a very unnatural walk. Other kinds of vibration can also affect the quality and look of the video you shoot. Shooting from a moving car or helicopter introduces a great deal of vibration, both from the vehicle itself and from your reactions to the movement of the vehicle.
Wind is another source of concern.
It doesn't matter how still you are, a sudden gust of wind is almost always going to affect your shot. Thankfully, there are solutions to all of these problems. They come in different forms, have different costs and are best suited for different types of shots, but they are available. Best of all, some very significant announcements were just made that are bound to change the way people look at stabilization. This is the type of product that is usually mounted to a news helicopter so that as the chopper flies around, it can broadcast stable images back to the ground.