A microelectrode was used to stimulate motor neurons in the lumbo-sacral spinal cord of adult cats. Consistent with spinal cord anatomical studies, we found that the motor neurons responsible for activation of individual muscle groups are situated together in specific areas of the cord, forming motor pools. Localized spinal cord stimulation of these motor pools enables selective activation of individual muscle groups. By modulating the magnitude of stimulation at different sites in the motor pools, we should be able to selectively activate different muscle groups to produce desired levels of contraction and controlled limb movements.
