Orthoses and Electrical Stimulation for Walking in Complete Paraplegia

Abstract

Orthotic systems, orthoses combined with functional neuromuscular stimulation (FNS), and FNS systems alone, are compared for their safety, function, and ease of use as walking systems for people with complete paraplegia. Despite the safety and joint protection offered by orthoses, the majority of paraplegics with lesions above the T-1 2 level discard braces at the termination of the rehabilitation period. Reasons include the limited function provided, poor cosmetic appearance, and high energy cost of use. Conventional bracing has been combined with FNS to facilitate the swing phase of gait, but the disadvantages of braces are still present; the advantage of slightly reduced energy cost with FNS is offset by the drawback of increased complexity. Trials of both surface and percutaneous FNS systems have demonstrated that FNS walking for paraplegics is feasible in the research environment. While pure FNS systems eliminate the disadvantages of bracing, they have the requirements of complex electrode application in the case of surface systems, or care of electrode skin sites and connections in the case of percutaneous systems. Additional problems of FNS systems are a high energy cost and lack of trunk and hip stability, requiring the use of a walker. The authors are addressing these problems through the development of closed-loop control of stimulation to utilize muscles in more normal on/off cycles and in the development of totally implanted systems to increase reliability and convenience.