Sight, taste, touch, smell, and hearing are not the only senses we have. Even a little research will reveal that we have at least double the amount, and our sense of balance and acceleration is one of those extra five. The only reason one thinks that there are only five senses is because of general ignorance.
If anyone is wondering, the other four are temperature, which is the change of heat in our nerves, kinesthetic sense, which is our sense of our relative body positions, pain, which is the detection of damage to our nerves, and time, which is how we perceive time to pass.
Of course it should. Our vestibular systems are arguably our most important sense, since without them we would be unable to function in the world. A quick Google search will show that it is often considered a sixth sense; its a mystery to me why it isn't ranked up there with sight and smell.