CORRECTION OF BI-LATERAL DROPPED FOOT USING THE ODSTOCK 2 CHANNEL STIMULATOR (O2CHS)

A single dropped foot can be successfully corrected using a single channel stimulator controlled by a foot switch. When an individual has bilateral dropped foot using two independent devices presents the difficulty that both channels can be active simultaneously, putting the user in an unstable situation. The O2CHS is a two channel device which can be controlled by one or two foot switches. The sequence of stimulation can be selected using internal switches and trimmer controls. For Bilateral dropped foot a single heel switch is used, channel 1 is triggered by heel rise and ended by heel strike. Channel 2 is triggered by heel shrike and ended by heel rise. For all but the fastest walker it was found necessary to add a short delay between the channels, after heel strike. Performance with the device was measured using walking speed and physiological cost index (PCI). Twenty subjects used the device (11 multiple sclerosis, 2 spinal cord injured, 1 stroke, 1 cerebral palsy and 5 with other spinal pathologies) of mean age 50.4 years. There was a mean increase in speed of 22.4% (p=0.022) and reduction in PCI of 12.2% (p=0.018) when the O2CHS was first used. For more able users, use of the device enables greater distances, reducing the risk of falling due to tripping. For the less able it enables mobility over short distances, delaying final dependence on the wheel chair.