The primary aim of this study is to:

1. Collect pilot data on the effect of task-specific lower extremity training using the Anklebot on subjects with Multiple Sclerosis (MS) and who have foot drop;
2. Collect pilot data on the use of combination therapy on improving gait in subjects with MS. This therapy will use both Anklebot training and robot-assisted gait training.

Hypothesis: Both trainings will result in improved walking performance, but the combination therapy will result in greater gains than ankle training alone.

Inclusion Criteria:

• Clinical diagnosis of MS by McDonald criteria (McDonald, Compston et al. 2001). EDSS level between 3.5-5.5, who report ambulation problems.
• Presence of unilateral foot drop that is clinically apparent to the PI or PI designate.
• Must be able to ambulate 25 feet without an assisting device.

Exclusion Criteria:

• Cardiovascular: recent MI < 4 wk, uncontrolled HTN >190/110 mmHg.
• History of uncontrolled diabetes.
• Symptoms of orthostasis when standing up.
• Circulatory problems, history of vascular claudication or pitting edema.
• Unable to fully understand instructions in order to use the equipment or the process of the study.
• Body weight over 150 kg.
• Lower extremity injuries that limit range of motion or function.
• Joint problems (hip or leg) that limit range of motion or cause pain with movement despite treatment.
• Unstable fractures.
• Pressure sores with any skin breakdown in areas in contact with the body harness or Lokomat apparatus.
• Chronic and ongoing alcohol or drug abuse.
• Pre-morbid, ongoing depression or psychosis.
• Ongoing physical therapy.
• Pregnancy (self-reported)
• PI's determination of inability to complete the test protocol