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.