Frequency ramped bursts.
A) Representative measurements of the tensile forces generated during application of a frequency ramped bursts lasting just less than 5s incorporating frequencies of 1, 5, 10, 20, 40, 60, 80 and 100 Hz at amplitudes of 0.5, 1.0, 1.5 and 2.0 mA using SpillOver stimulation. B) Averaged force frequency curves for supra-maximal stimulation of the common peroneal nerve at unloaded concentric (dashed black trace) and isometric (solid black trace) contractions, along with SpillOver contractions at different amplitudes. SpillOver stimulation at high frequency (above 70 Hz) was able to elicit forces in the tibialis anterior muscle higher than those produced during isometric contraction. Data is presented as mean peak force and SEM for UNL and ISO contractions, SpillOver contractions are only illustrated as mean peak force for better comparison.