The gait symptoms are usually refractory to the dopaminergic agents and some other resolutions, i.e. repetitive transcranial magnetic stimulation (rTMS) should be searched for in this regard. To study the impact of rTMS, investigators will adopt a domestically developed ambulatory recorder (PK-16CH EXG) for the concomitant recording of the electroencephalographic and electromyographic signals for PD patients when walking in the gait laboratory or when conducting leg dorsiflexion movement on sitting.