QUALITY-OF-LIFE TECHNOLOGY Technology for Mobility and Quality of Life in Spinal Cord Injury M ore than 200,000 people in the United States have spinal cord injuries (SCIs), and each year 10,000 new cases occur [1], [2]. Individuals with SCIs have limited mobility because of the loss of vol- untary muscle control and limitations in sensory, autonomic, reflexes, and visceral organ functions. Secondary complica- tions arising from these limitations include muscle atrophy, osteoporosis, abnormal thrombus formation, pressure ulcer formation, urinary tract infection, heart disease, and cardio- pulmonary deconditioning. These secondary conditions prev- alent after an SCI can lead to a general decrease in community participation and, thus, reduced quality of life. Conventional rehabilitation following an SCI is usually de- signed to facilitate recovery through strengthening and endurance training of unaffected muscles and compensation strategies for accomplishing mobility [3]. Many devices have been developed to improve the mobility of individuals with SCI. Because of the multiplicity of these devices, health professionals are always chal- lenged with the choice of identifying the best mobility devices that are functional, cosmetically appropriate, feasible, and efficient. The purpose of this article is to provide a review of mobility devices available for the rehabilitation of individuals with SCI. The technologies that improve mobility and potentially enhance community participation that will be discussed include those devices that are used to improve ambulation, wheeled mobility, and functional electrical stimulation (FES) systems. This review should provide a guide to biomedical engineers to understand the tools developed, the design characteristics, and the functionality of such technologies that strive to improve functional mobility of individuals with SCI. This review is not intended to suggest the optimal device(s) geared for a given individual with SCI. Con- versely, since it is important to match the person with the technology, the purpose of this review is to offer a series of mobility options that may be available to a person with SCI. A brief description of the definition of an SCI is warranted prior to understanding the needs for mobility technologies that may lead to improved quality of life. An SCI occurs as a result of an injury to the spinal cord, a part of the central nervous system, and as a result of trauma, infection, or disease. When the injury occurs in the cervical (neck) region between cervical levels 1 and 7, this is referred to as tetraplegia, previously quadriplegia. This means that all four limbs are affected. These injuries, when com- plete, result in full paralysis of the legs and partial paralysis of the trunk and arms. There is also a loss of sensation, which can lead to pressure ulcers if there is improper seating or weight relief. If the injury is in the thoracic (trunk) region or the lumbar (low back) region, resulting paraplegia ensues. In this case, the arms are fully functional, and if complete, there is partial paralysis of the trunk and the legs are completely paralyzed. In many cases, SCI results in an incomplete injury that may include a person having only some feeling (sensation) below the injury level or some ability to contract the muscles and move the limbs below the injury level. When there is an incom- plete injury, the term paresis can be used, such as paraparesis. Depending on the degree of paralysis and the expected recovery from injury, decisions about mobility devices are made by the rehabilitation team. This team can include physicians, physical and occupational therapists, rehabilitation or biomedical engi- neers, assistive technology specialists, and the patient or client. Gait Rehabilitation after an SCI Injury to Improve Ambulation Mobility Following rehabilitation, one quarter to one third of patients with SCI may regain some locomotor function by the time of dis- charge [4], [5]. Typically, conventional rehabilitation therapy uses compensation strategies such as canes, crutches, and walk- ers to improve locomotor behavior to accomplish mobility. Without these devices, individuals would need to rely on wheel- chair mobility [6]. Although these assistive walking devices allow for independent and community ambulation, they do alter axial loading and compromise walking kinematics and momen- tum to limit the capacity of the locomotor behavior. Specifically, walkers used during overground locomotion to support weak- ened limbs can provide up to 100% body weight support, pro- mote an adaptation of increased trunk flexion, and decrease the walking speed. Elbow crutches, when compared with walkers, provide less support and trunk flexion and allow for faster walk- ing speeds, and cane users (straight cane with a T handle) allow for a propulsive assistance to increase walking speed, with the least amount of vertical support [7]. Within the last decade, one of the most promising approaches in rehabilitation after SCI to promote locomotion recovery has BY SUE ANN SISTO, GAIL F. FORREST, AND POURAN D. FAGHRI ©DREAMSTIME, ISTOCKPHOTO, PHOTODISC Digital Object Identifier 10.1109/EMB.2007.907398 Analyzing a Series of Options Available 56 IEEE ENGINEERING IN MEDICINE AND BIOLOGY MAGAZINE 0739-5175/08/$25.00©2008IEEE MARCH/APRIL 2008