A comparison of knee-extension torque production with biphasic versus Russian current

Context: Neuromuscular electrical stimulation (NMES) can be used to prevent the atrophy and strength loss associated with immobilization. Objective: To compare the effects of biphasic current and the modulated "Russian" current on muscular torque production during different contraction conditions. Design, Setting, and Participants: In a within-subjects design, 10 healthy subjects in an athletic training laboratory received NMES. Interventions: Isometric knee-extension torque was recorded with the Biodex(TM) under 4 conditions: maximum voluntary contraction (MVC; control), MVC superimposed with low-intensity stimulation (sham), MVC superimposed with high-intensity stimulation, and high-intensity stimulation only. Main Outcome Measure: Data normalized for body weight were analyzed using a 2 (current type) x 4 (condition) repeated-measures analysis of variance. Results: The main effect for current type was not significant, F-1,F-9 = .03, P = .87. Conclusions: There is no difference in the effectiveness of biphasic and Russian currents when they are used to elicit forceful muscular contractions.