Hello ItsWonderfulLife and welcome to NeuroTalk.
In regards to MS: Exercise has been shown to be beneficial. A Physical Therapist (PT) can help get you started. Weakness, for some can be improved but it can take time, effort and frustration on the part of the patient. Unfortunately, a person with MS will not know if their weakness can be improved without making an effort.
Not everyone or every case of weakness can be improved but it is important to continue exercise/PT. What exercises depends on the persons ability.
http://www.nationalmssociety.org/liv...ise/index.aspx