Comparison of the pedalling performance induced by magnetic and electrical stimulation cycle ergometry in able-bodied subjects

The purpose of the study was to compare the mechanical power and work generated by able-bodied subjects during functional magnetic stimulation (FMS) vs. functional electrical stimulation (FES) induced ergometer training conditions. Both stimulation methods were applied at a 30 Hz frequency to the quadriceps muscles of 22 healthy able-bodied subjects to induce cycling for 4x four minutes or until exhaustion. FMS was performed via large surface, cooled coils, while FES was applied with a typical stimulation setup used for cycling. Significantly more (p < 10(-3)) muscular power was generated by FMS (23.8 +/- 9.1W [mean +/- SD]) than by FES (11.3 +/- 11.3W). Additionally, significantly more (p < 10(-6)) work was produced by FMS than by FES (4.413 +/- 2.209 kJ vs. 0.974 +/- 1.269 kJ). The increase in the work was paralleled by a significant prolongation of time to cycling failure (181.8 +/- 33.4s vs. 87.0 +/- 54.0 s, respectively, p < 10(-5)). Compared to FES, FMS can produce more intense and longer cycling exercise in able-bodied subjects. The differing dynamic behaviour of FMS and FES in the presented measurement setup might be related to stimulation induced pain and fatigue mechanisms of the neuromuscular system. (C) 2013 IPEM. Published by Elsevier Ltd. All rights reserved.