Secondary progressive multiple sclerosis (SPMS) is a subtype of multiple sclerosis (MS) for which there are no existing therapies that alter the disease course. This research will utilize cutting edge functional electrical stimulation (FES) cycling technology with the goal of improving walking in individuals with SPMS. The investigators hypothesize that FES cycling will improve walking in subjects with SPMS.

Individuals with secondary progressive multiple sclerosis (SPMS) experience significant impairments in ambulation leading to use of canes, walkers, and ultimately wheelchairs. Treatment attempts for progressive MS have been disappointing. No therapeutic intervention has been shown to modulate disability in patients with SPMS. FES cycling has been shown to have multiple primary medical benefits including: increased muscle mass, improvements in bone density, enhanced cardiovascular function, improved bowel function, decreased spasticity and reductions in bladder infection rate. More importantly FES may modulate the inflammatory central nervous system (CNS) environment in progressive MS. The investigators are proposing a novel, and easy to implement intervention strategy of FES cycling to help improve gait function in individuals with SPMS. A successful outcome on a larger SPMS population would have significant impact towards changing MS clinical care. FES is easily transferable to clinical practice and could potentially ameliorate other complications associated with SPMS such as spasticity, mood and fatigue reducing the burden of health care cost. In addition, the investigators will gain a better understanding of the mechanisms underlying these changes that could be used to design new therapeutic strategies.

Inclusion Criteria:

• clinical diagnosis of secondary progressive multiple sclerosis
• males and females between the ages of 18 and 65 years
• Expanded disability status scale score between 5.0 and 7.0
• Able to consent to participate in study and are willing to undergo a lumbar puncture and blood draws
• If on on Ampyra or anti-spasticity agent, must be on stable dose for 1 month prior to screening
• No functional electrical stimulation use within 4 weeks
• Participants must be medically stable with no recent (1 month or less) inpatient admission for acute medical or surgical issues

Exclusion Criteria:

• Uncontrolled hypertension or other significant cardiovascular disease as determined by investigator
• History of epileptic seizures
• Subjects who have a pacemaker
• Relapse within thirty days prior to screening visit
• Pregnancy
• Subjects having a Stage 2 or greater sacral decubitus ulcer