Subjects having bilateral electrical stimulation and task-orientated exercises

Subjects having unilateral TENS over their affected lower limb only, and task-oriented exercises

All subjects will undergo 16 sessions of their assigned intervention (60 minutes, twice a week, for 8 weeks). All subjects will receive 60 minutes task-oriented lower limb training (TOT) with electrical stimulation protocol assigned concurrently:

The strength of maximum isometric voluntary contraction of the subject's knee extensors and flexors, ankle dorsiflexors, and plantarflexors (in kilograms) will be measured bilaterally using a Nicholas handheld dynamometer (model 01,160, Lafayette Instrument Company, Lafayette, IN) with standardized testing positions and dynamometer placement. Good to excellent reliability (ICC range, 0.84 -0.99) has been reported for lower-limb hand-held dynamometer strength measurements of subjects with neurologic conditions [49]. Each subject will complete three trials in which maximal force is generated for 2 to 3 seconds ffrom each muscle. The average of the three readings will be used for data analysis.

The step test (ST) will be used to measure dynamic standing balance of both the paretic and normal limbs. It measures the number of times a subject is able to place one foot on a step 7.5cm high and back to the ground, as fast as possible, within 15 seconds. Three trials will be performed with each leg, with 1 minute of rest between trials to minimize fatigue. ST scores show excellent intra-rater and inter-rater reliability with subjects with chronic stroke.

The lower-extremity motor coordination test (LEMOCOT) will be used to measure the coordination of both the paretic and normal legs [50]. The LEMOCOT has been demonstrated as having good reliability (ICC=0.83-0.88) for subjects with subacute stroke [50]. Two red flat targets will be secured on the floor 30cm apart. The test will be performed while the subject is seated on a chair without armrests, with the knees flexed at close to 90o, the feet resting flat on the floor, and the heels on one of the targets. The subject will be instructed to touch the 2 targets alternately with the big toe, as quickly and as accurately as possible, for 20 seconds. The number of times each target is touched will be counted. The first trial will be a practice trial, with the average of the second and third trials used for analysis.