Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) rippling muscle disease ?
    ### Response:
    Rippling muscle disease is a condition in which the muscles are unusually sensitive to movement or pressure (irritable). The muscles near the center of the body (proximal muscles) are most affected, especially the thighs. In most people with this condition, stretching the muscle causes visible ripples to spread across the muscle, lasting 5 to 20 seconds.
    