Hi:
The limb movements are of two sorts as far as I can tell. One is fluttering movements of surface muscles in arms, legs, trunk, and face. The other sort is some fairly strong jerks of muscles in the upper legs and arms. These latter are often associated with spasms that may be very short in duration or may progress to major cramps that only respond to standing or some strong pressure and cause soreness. Fatigue worsens both.
Bruce