Validation of Hand Held Dynamometer for Assessment of Lower Limb Muscle Strength in Multiple Sclerosis

Inclusion Criteria: * Stable patients with clinically definite Multiple Sclerosis * No Multiple Sclerosis exacerbation 30 days prior to screening * No change in disease modifying therapy for 30 day prior to screening Exclusion Criteria: * Inflammatory myopathy * Endocarditis, pericarditis o rother unstable heart disease * Cardiac surgery or myocardial infarction in the last 3 months * Decompensated congestive heart failure * Severe aortic stenosis * Severe pulmonary hypertension * Pulmonary embolus or infarction in the last 6 months * Uncontrolled hypertension by history or by screening or baseline diastolic blood pressure \>170 or systolic blood pressure \>105 * Concomitant neurodegenerative neurological disease such as Amyotrophic Lateral Sclerosis (ALS) Parkinsons or hemiplegic stroke * females who are pregnant * Cognitive deficits that would interfere with the subjects's ability to give informed consent or preform study testing * Painful orthopedic condition affecting the lower limbs * Any other serious and/or unstable medical condition