Electrical muscle stimulation in combination with a reciprocating gait orthosis for ambulation by paraplegics

Commercially available electrical muscle stimulators (EMS) provide functional electrical stimulation and are interfaced with reciprocating gait orthosis (RGO). The system which has been developed is described here as an EMS-RGO. Advantages of the system include: medically prescriptable subsystems available from manufacturers, and commercially recommended subsystems for applications such as gait training. The system itself employs four EMS units worn on a belt. It is controlled by remote switches and is interfaced to electrodes placed over the quadriceps, hamstring and gluteal muscle groups of each leg. Two EMS units (for quadriceps stimulation) function primarily for stand-up and sit-down. Two other EMS units (for stimulation of the hip extensors) function primarily for ambulation. Each EMS unit is powered by a nine volt alkaline transistor battery which provides about 36 stand-uphs and sit-down's and approximately 3.1 km of walking before replacement is necessary. The system has been evaluated on a T-5 level paraplegic individual who sustained a motor complete lesion (Frankel Class B) of the spinal cord over seven years ago. It is emphasized that successful EMS-RGO walking exercise must be preceded by a physical conditioning programme of active physical therapy. New battery technology (such as lithium batteries) may improve the useful lifespan of the system, and new electrode technology (such as TTGs) may improve patient acceptance of the system.