A Comparison of Functional Electrical and Magnetic Stimulation for Propelled Cycling of Paretic Patients

Isometric and cycling measurement setup. Both FMS and FES stimulation are possible. A subject with complete SCI performing FMS-propelled cycling using 2 magnetic stimulators can be seen. (1) torque transducer, (2) angular encoder, (3) right side repetitive magnetic stimulator, (4) left side coil, (4, 5) straps made of foam and Velcro. Inset: definition of the crank angle.

Isometric measurements performed on a representative subject belonging to the stroke group. Starting from the motor threshold, stepwise-increasing FES and FMS burst amplitudes were applied until maximum tolerable intensity was reached in the first and the last part of the protocol, respectively. Combined stimulation (the FMS burst sequence was superimposed on the FES) was applied in the middle part of the protocol.

Isometric measurements performed on a representative subject belonging to the SCI group. In the first part of the test, starting from the motor threshold, stepwise-increasing FMS burst amplitudes were used until maximal intensity was reached. In the second part of the test, combined stimulation was applied (the FMS burst sequence was superimposed twice on the FES).

Cadence (upper graph) and crank torque (lower graph) profiles measured in a subject of the stroke group with right hemiparesis during volitional (gray) and FMS-supported volitional (black) cycling conditions taken over 15-second periods. Measurement points and 10th-order polynomial fitting curve are represented. Abbreviation: QUAD, stimulation interval of the right quadriceps.

Isometric torque, power, smoothness, and symmetry of n=29 chronic poststroke patients with hemiplegia measured under volitional, FMS, and FES stimulation conditions. Bars and segments plotted represent group means ± SDs. *FMS compared with FES with significance of P<.05; ^##stimulation compared with volitional with significance of P<.001. Abbreviation: VOL, volitional.

Isometric torque and power of n=11 patients with chronic complete SCI measured under FMS and FES stimulation conditions. Bars and segments plotted represent group means ± SDs. Significant comparisons of FES and FMS: *P=.003, **P<10⁻⁴, respectively.