A Comparison of Functional Electrical and Magnetic Stimulation for Propelled Cycling of Paretic Patients
Abstract
Szecsi J, Schiller M, Straube A, Gerling D. A comparison of functional electrical and magnetic stimulation for propelled cycling of paretic patients.
Objective
To compare isometric torque and cycling power, smoothness and symmetry using repetitive functional magnetic stimulation (FMS) and functional electrical stimulation (FES) in patients with paretic legs with preserved sensibility and in patients without sensibility.
Design
Repeated-measures design.
Setting
Laboratory setting.
Participants
Eleven subjects with complete spinal cord injury (SCI) and 29 subjects with chronic hemiparesis (16.6±5.5mo poststroke) volunteered.
Interventions
Using a tricycle testbed, participants were exposed to isometric measurements and ergometric cycling experiments, performed during both 20Hz FMS and FES stimulation. Subjects with hemiparesis and with complete SCI were stimulated at maximally tolerable level and maximal intensity, respectively.
Main Outcome Measures
Maximal isometric pedaling torque and mean ergometric power, smoothness, and symmetry were recorded for voluntary, FES, and FMS conditions.
Results
Two different patterns of the efficacy of FMS were identified. (1) Patients with complete SCI did not benefit (less torque and power was evoked with FMS than with FES, P<.003 and 10−4 respectively). (2) Patients with hemiplegia and preserved sensibility could improve their torque output (P<.05), smoothness, and symmetry of pedaling (P<.05) with FMS more than with FES.
Conclusions
FMS is a potential alternative to surface FES of the large thigh musculature in stimulation-supported cycling of patients with partially or completely preserved sensibility.
aCenter for Sensorimotor Research, Department of Neurology, Ludwig-Maximillians University, Munich, Germany
bDepartment of Electrical Drives, University of Federal Defense, Munich, Germany
Correspondence to Johann Szecsi, MD, Center for Sensorimotor Research, Dept of Neurology, Ludwig-Maximillians University, Marchioninistrasse 23, 81377 Munich, Germany
Supported by the Else-Kröner Fresenius Foundation, Bad-Homburg, Germany (grant no. P35/06//A09/06).
No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit on the authors or on any organization with which the authors are associated.
ABSTRACT