What Causes Severe Vibrating Sensation In The Lower Leg?

I have been experiencing internal vibration of lower leg muscles similar to feeling vibrations coming up from the floor to one s legs and feet from machinery operating on the floor below. Also I cannot sleep for more than 3 to 4 hours before I am awakened by a storm of these vibrations all over my body, particularly in the core of my torso. If I sit up and breath deeply to relax, it all gradually subsides except the leg muscles. When I am up moving around, the leg vibrations are not noticeable. They become noticeable when I sit down and try to relax.