Double blind randomized study including 40 patients with MS. The patients will be randomly allocated into 2 arms: active arm and placebo arm; in the active arm patients will receive "high tone power therapy" in addition to the physical therapy conventional selected exercise program, and the placebo arm will receive the same physical exercise program with sham "high tone power therapy". Either program will be applied 3 times per week for 4 weeks.
The evaluation methods will be done using:
* Expanded Disability Status Scale (EDSS) / Functional Systems Score (FSS),
* Fatigue severity scale and Modified Fatigue Impact Scale. before the exercise program and after finishing the exercise program, The assessor of the patients, before and after the program, will be blinded to the technique used (whether active or sham).
