Under the proposition that tetanic contractions are not set up by currents, which current is the correct answer?

• A. Low Frequency Current
• B. High Frequency Current
• C. Both
• D. Neither

Answer: (B)

Tetanic contraction happens when stimulation is so frequent that individual muscle twitches overlap and fuse into one smooth, sustained contraction. Low-frequency currents produce separate twitches with periods of relaxation between pulses, so they don’t create tetanus. High-frequency currents deliver impulses quickly enough to cause summation and fusion of contractions, often in bursts that maximize the fused response. So, to achieve a tetanic contraction with electrical stimulation, the high-frequency current is the appropriate choice.