Dual transcranial direct current stimulation (tDCS) will be applied over the leg motor area (M1) during the first 20 mins of conventional physical therapy (about 1 hours). Anodal on affected hemisphere, Cathodal on unaffected hemisphere. Current intensity is fixed at 2 mA and current will flow continuously during 20. Physical therapist will give an intervention program exactly the same in all cases. The scope of intervention is administered to improve strength of weakened and postural lower limbs muscles such as trunk muscles, hip flexors/extensors/abductors, knee flexors/extensors.

Dual transcranial direct current stimulation (tDCS) will be applied over the leg motor area (M1) during the first 20 mins (sham mode) of conventional physical therapy (about 1 hours). Anodal on affected hemisphere, Cathodal on unaffected hemisphere. Physical therapist will give an intervention program exactly the same in all cases. The scope of intervention is administered to improve strength of weakened and postural lower limbs muscles such as trunk muscles, hip flexors/extensors/abductors, knee flexors/extensors.

Dual Active/sham tDCS will be applied over the leg motor area (M1) during the first 20 mins of conventional physical therapy. Anodal on affected hemisphere, Cathodal on unaffected hemisphere. Each participant will complete two experiments (active/sham tDCS). The interval between two experiments is at least 2 weeks. The two experiments will be performed in random order for each subject.

sling. Subjects will be instructed as the following "I want you to stand up and sit down 5 times as quickly as you can when I say 'Go'." Subjects must be fully standing between repetitions. Timing will begin at "GO" and ends when the patient's buttocks touch the seat after the fifth sit-to-stand.

Subjects will sits on the chair and place their back against the chair. Timing will begin at "GO", the subjects will be asked to walk 3m, turn, walk back, and sit down. The stopwatch stops when the patient's buttocks touch the seat.