Walking after incomplete spinal cord injury using an implanted FES system: A case report

Elizabeth Hardin, Rudi Kobetic, Lori Murray, Michelle Corado-Ahmed, Gilles Pinault, Jonathan Sakai, Stephanie Nogan Bailey, Chester Ho, Ronald J. Triolo
2007 Journal of rehabilitation research and development  
Implanted functional electrical stimulation (FES) systems for walking are experimentally available to individuals with incomplete spinal cord injury (SCI); however, data on short-term therapeutic and functional outcomes are limited. The goal of this study was to quantify therapeutic and functional effects of an implanted FES system for walking after incomplete cervical SCI. After robotic-assisted treadmill training and overground gait training maximized his voluntary function, an individual
more » ... , an individual with incomplete SCI (American Spinal Injury Association grade C, cervical level 6-7) who could stand volitionally but not step was surgically implanted with an 8-channel receiver stimulator and intramuscular electrodes. Electrodes were implanted bilaterally, recruiting iliopsoas, vastus intermedius and lateralis, tensor fasciae latae, tibialis anterior, and peroneus longus muscles. Twelve weeks of training followed limited activity post-surgery. Customized stimulation patterns addressed gait deficits via an external control unit. The system was well-tolerated and reliable. After the 12-week training, maximal walking distance increased (from 14 m to 309 m), maximal walking speed was 10 times greater (from 0.02 m/s to 0.20 m/s), and physiological cost index was 5 times less (from 44.4 beats/m to 8.6 beats/m). Voluntary locomotor function was unchanged. The implanted FES system was welltolerated, reliable, and supplemented function, allowing the participant limited community ambulation. Physiological effort decreased and maximal walking distance increased dramatically over 12 weeks. Abbreviations: ASIA = American Spinal Injury Association, BP = breakpoint, BWS-TT = body-weight-supported treadmill training, CV = coefficient of variation, EMG = electromyographic, FAC = Functional Ambulation Category, FES = functional electrical stimulation, MET = metabolic equivalent, MMT = manual muscle test, OGW = overground walking, PCI = physiological cost index, RF = respiration frequency, SCI = spinal cord injury, SCI-FAI = SCI Functional Ambulation Inventory, TFL = tensor fasciae latae, TV = tidal volume, = oxygen consumption. * Repeatability of FES + Volitional was better than Volitional alone (p < 0.05) for all conditions, as signified by decreased CV. † Post-implant right knee movement with FES was less than post-implant with FES + Volitional (p < 0.05). CV = coefficient of variation, expressed as percentage (used to determine repeatability); SD = standard deviation. * Significantly different change of ≥20% (p < 0.05) between mid-training and post-training with implant; considered clinically significant. CV = coefficient of variation (expressed as percentage), SD = standard deviation.
doi:10.1682/jrrd.2007.03.0333 fatcat:qnrkrq5lanbmrmvzpujxz5vmiu