Long-term therapeutic and orthotic effects of a foot drop stimulator on walking performance in progressive and nonprogressive neurological disorders.
BACKGROUND
Stimulators applying functional electrical stimulation (FES) to the common peroneal nerve improve walking with a foot drop, which occurs in several disorders.


OBJECTIVE
To compare the orthotic and therapeutic effects of a foot drop stimulator on walking performance of subjects with chronic nonprogressive (eg, stroke) and progressive (eg, multiple sclerosis) disorders.


METHODS
Subjects with nonprogressive (41) and progressive (32) conditions used a foot drop stimulator for 3 to 12 months while walking in the community. Walking speed was measured with a 10-m test and a 4-minute figure-8 test; physiological cost index (PCI) and device usage were also measured. The subjects were tested with FES on and off (orthotic effect) before and after (therapeutic effect) stimulator use.


RESULTS
After 3 months of FES use, the nonprogressive and progressive groups had a similar, significant orthotic effect (5.0% and 5.7%, respectively, P < .003; percentage change in mean values) and therapeutic effect with FES off (17.8% and 9.1%, respectively, P < .005) on figure-8 walking speed. Overall, PCI showed a decreasing trend (P = .031). The therapeutic effect on figure-8 speed diverged later between both groups to 28.0% (P < .001) and 7.9% at 11 months. The combined therapeutic plus orthotic effect on figure-8 speed at 11 months was, respectively, 37.8% (P < .001) and 13.1% (P = .012); PCI decreased 18.2% (P = .038) and 6.5%, respectively.


CONCLUSIONS
Subjects with progressive and nonprogressive disorders had an orthotic benefit from FES up to 11 months. The therapeutic effect increased for 11 months in nonprogressive disorders but only for 3 months in progressive disorders. The combined effect remained significant and clinically relevant.
University of Alberta, Edmonton, Alberta, Canada. Richard.Stein@UAlberta.Ca
Richard B
RB
Stein
Dirk G
DG
Everaert
Aiko K
AK
Thompson
Su Ling
SL
Chong
Maura
M
Whittaker
Jenny
J
Robertson
Gerald
G
Kuether
D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D018450:Disease Progression; D004599:Electric Stimulation Therapy / Q000295:instrumentation* / Q000379:methods*; D005081:Exercise Therapy; D005260:Female; D005528:Foot / Q000294:innervation*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009422:Nervous System Diseases / Q000145:classification / Q000503:physiopathology / Q000534:rehabilitation*; D009989:Orthotic Devices; D010543:Peroneal Nerve / Q000502:physiology; D013997:Time Factors; D016138:Walking / Q000502:physiology*; D055815:Young Adult