Vibrations responsive to muscle contraction

[geist]

Hi, I just want to know if it's normal. Once I install those inner oscillations (swaying motion) I can stand up and walk. But every muscle that contract, makes oscillatory movements, in that area, get stronger and in a higher pitch.
That makes my walking just like I'm carrying balloons filled with water. Keeps vibrating at each step. If I close my hand (hard), I can feel the same.
Is it really a vibrational state?
Is it normal?
Does anyone feel the same?
Thanks