Functional Electrical Stimulation and Lower Extremity Bracing for Ambulation Exercise of the Spinal Cord Injured Individual: A Medically Prescribed System

The purpose of this study was to determine whether commercially available electrical muscle stimulators could provide functional ambulation exercise for the spinal cord injured individual. Commercially available electrical muscle stimulators were used for functional electrical stimulation and interfaced with reciprocating gait orthoses so that a new system has been developed. Advantages of the system include commercially available subsystems and subsystems for applications such as gait training. The system involves six electrical stimulation units worn on a belt; controlled by remote switches; and interfacing to electrodes placed over the quadriceps femoris, hamstring, and gluteal muscle groups of each leg. Four electrical stimulation units (for quadriceps femoris muscle stimulation) function primarily for stand-up and sit-down activities. Two other units (for stimulation of the hip extensor muscles) function primarily for ambulation. The system is described for use with a C7-level quadriplegic individual. The patient successfully performed over 20 repetitions of stand-up and sit down exercises with the system. An average walking distance of about 0.8 km was routinely traversed at velocities ranging from 1.2 to 2.0 km per hour. It was concluded that muscle fatigue, rather than battery power, was the functionally limiting factor for the quadriplegic patient. A recommendation is that application of the system for walking exercise should be preceded by a physical conditioning program of functional electrical stimulation. Specific medical criteria should be satisfied prior to formally prescribing the system for an individual. Finally, the steps involved in the writing of the walking system prescription are outlined.