Affiliations: [a] Fujita Memorial Nanakuri Institute, Fujita Health University, Aichi, Japan | [b] Fujita Health University, Nanakuri Memorial Hospital, Mie, Japan
Correspondence:
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Corresponding author: Genichi Tanino, Fujita Memorial Nanakuri Institute, Fujita Health University, 423 Oodori, Tsu, Mie 514-1296, Japan. Tel.: +81 59 252 2741; Fax: +81 59 252 0710; E-mail:gtanino@fujita-hu.ac.jp
Abstract: BACKGROUND: Electrical stimulation is shown to be effective for the
amelioration of paralysis. The stimulation pattern can have a direct
relation to injected charge in the stimulated area resulting in a wider area
stimulation and consequently better recovery. OBJECTIVE: In this study, we investigated the effect of two
electrical stimulation waveforms, rectangular and exponentially climbing.
Three parameters of current, voltage, and knee extension torque of the 2
waveforms were recorded and used for the comparison of the two waveforms. METHODS: Fifteen male and 15 female able-bodied subjects (age: 25.0
± 3.2) were recruited. Electrical stimulation was applied to right
quadriceps muscles. At the maximum tolerable intensity, the 3 parameters
were recorded for each of the 2 waveforms. Using the recorded knee extension
torques, the adjusted maximum electrically induced contraction to voluntary
torques in percent (%MEIC) of the two waveforms were calculated. Together
with the other two parameters, current and voltage, the 2 waveforms were compared. RESULTS: The %MEIC and maximum voltage were significantly higher
with the exponentially climbing waveform than with the rectangular waveform
(%MEIC: p < 0.05, max voltage: p < 0.01). The maximum current did not differ
significantly between conditions. CONCLUSION: These results indicate that an exponentially climbing
waveform may induce stronger torque than a rectangular waveform and might
thus be useful when applying NMES in clinical situations.
