Effect of Combining Central and Peripheral Cutaneous Electrical Stimulation on Lower Limb Motor Function in People With Stroke

tDCS will be delivered by a constant-current electrical stimulator (DC-stimulator; Eldith, Ilmenau, Germany). Rectangular electrodes covered with a saline-soaked sponge will be used for the anode and cathode. The anode will be placed over the leg area of the motor cortex, on the lesioned side, with the medial border of the electrode placed laterally to Cz on the international electroencephalogram 10-20 system. The cathode will be placed above the contralateral orbit. The stimulation intensity will be set at 2 mA for 30 minutes.

Sham tDCS will be delivered by a constant-current electrical stimulator (DC-stimulator; Eldith, Ilmenau, Germany). Rectangular electrodes covered with a saline-soaked sponge will be used for the anode and cathode. The anode will be placed over the leg area of the motor cortex, on the lesioned side, with the medial border of the electrode placed laterally to Cz on the international electroencephalogram 10-20 system. The cathode will be placed above the contralateral orbit. The stimulation intensity will The stimulator will only be applied for the first and last 30 seconds.

TENS will be delivered to the common peroneal nerve of both intact and paretic leg for 30 minutes using a 120z Dual-Channel TENS Unit (ITO Physiotherapy \& Rehabilittaion, Co, Ltd, Tokyo, Japan). The TENS stimulation will be at 100 Hz, with 0.2 ms square pulses at an intensity of twice the sensory threshold (defined as the minimum intensity at which subject reported feeling a tingling sensation and below the motor threshold as indicated by the absence of muscle twitching.

Placebo-TENS will be applied to identical-looking TENS devices, with the electrical circuit disconnected inside the devices. Placebo-TENS will be delivered to the common peroneal nerve of both intact and paretic leg for 30 minutes that set at 100 Hz, with 0.2 ms square pulses.

The lower-limb task-oriented training comprises 5 exercises for 30 minutes, namely stepping up and down, heel lift a dorsiflexed position, partial squatting, gait re-education and transition training.