Biological invention: Artificial Muscle

This is an idea I got when I study this invention.

Everyone has the experience of twisting a wet tower to expel all the water it has soaked. It is difficult to achieve this goal if you had a mighty hand. Then I was thinking: Since tower itself wasn’t make to be a tough material, it is only this way of moving this tower creating the toughness in the tower.
So if I am going to design the muscle from the scratch, I would build muscle fiber using long chain of muscle cells surrounded a long axial cells. In the normal state, they are twisted clockwisely or anti-clockwisely to a smaller extent so the distance between two ends is shorter than its length if it is fully unscrewed. There is a central axial acting to fix the level of twisting of the outer muscle. Upon receive the message from the nervous system, the central axial would turn either more clockwisely or anti-clockwisely, thus the outer muscle would increase its extend of twisting. As the outer muscle is sticked into location. Therefore, it would become shorter as a result. Force is thus exerted by the outer muscle to do useful work.