Sham stimulation will be applied over quadriceps femoris and biceps brachii on both sides for 10 min to each muscle group, one at a time. Stimulation is delivered for 10 min to each muscle group, in three 10 minute sessions per week, for 4 weeks.

Three training sessions for 10 minutes per muscle group per week, for 4 weeks during which sham stimulation will be applied.

Trancutaneous Electrical Nerve Stimulation (TENS) stimulation applied quadriceps femoris and biceps brachii on both sides for 10 min to each muscle group, one at a time. Stimulation is delivered for 10 min to each muscle group, in three 10 minute sessions per week, for 4 weeks.

Three training sessions for 10 minutes per target muscle group per week, for 4 weeks during which Trancutaneous Electrical Nerve Stimulation (TENS) stimulation is applied quadriceps femoris and biceps brachii on both sides.

Transcutaneous Electrical Nerve Stimulation produces an electrical current to stimulate the nerves for therapeutic purposes. continuous high frequency (≥ 50 Hz) stimulation for 5 minutes followed by high frequency (≥ 50 Hz) bursts with 7 pulses per burst for the last 5 minutes.

This test assesses submaximal aerobic capactity. Subjects walk for 6 minutes starting at mark on the floor at the beginning of a 30-m long hallway and walk to the next mark at the end of the hallway as quickly as possible, but safely. The distance which is walked by the subject is measured. Subjects may use assistive devices when performing the task.

This test assesses functional lower extremity strength. Subjects sit on a chair and stand up repeatedly for 30 s. Arms of the subject are crossed and held against the chest. The number of cycles of standing up from sitting are counted.

This is a questionnaire related to the impact of fatigue on daily life. The questionnaire consists of 9 questions with a 7-point scale ranging from 'completely agree' to 'completely disagree'. The total score ranges from 9 to 63; higher scores reflect a higher impact.

This is a questionnaire related to sense of fatigue. The questionnaire consist of 21 questions providing assessment of the effect of fatigue in terms of physical, cognitive and psychosocial function. The total score ranges from 0 to 84; higher scores reflect a higher impact of fatigue.

This is a patient-base measure of walking ability. The questionnaire consists of 12 items with a 5-point scale ranging from 'not at all' to 'extremely'. The total score ranges from 5 to 60, with higher scores reflecting more walking difficulties.

Maximal voluntary force (MVC) of the elbow flexors is measured with a custom-built dynamometer. Subjects are seated in a chair with their arm abducted and in 90° of flexion with their non-dominant arm strapped to the force transducer. Subjects are instructed to contract their elbow flexors as rapidly and forcefully as possible and to maintain force generation for 5 s. MVC is determined as the peak force.

A self-report questionnaire with 54 items used to quantify health-related quality of life. Generates two separate composite scores for physical and mental health (0-100); higher scores indicate better quality of life.