Motor responses to implantable FES electrodes in a growing limb

A canine model was used to investigate the performance of surgically implanted epimysial and intramuscular electrodes in a growing limb. A total of 14 epimysial and 14 intramuscular electrodes were implanted in 7 skeletally immature dogs. Recruitment properties for the electrodes were measured at the time of implant and one year later using tendon tension transducers. The measurements of threshold for target muscle activation and threshold for spillover show that appropriate muscle recruitment order was retained in 93% electrodes that were evaluated, despite increase in limb length of up to 6.5 cm