Tetany in NMES occurs when frequency is increased to the point that what happens?

Tetany in NMES occurs when frequency is increased to the point that what happens?

• A. A smooth contraction with visible twitches
• B. A tremor occurs during contraction
• C. A plateau in force output
• D. Individual twitches are not discernible

Answer: (D)

When the stimulation frequency rises, individual motor unit twitches begin to overlap in time and sum up, creating a smooth, sustained contraction known as fused tetanus. At this point the impulses come so fast that you can’t see separate twitches—the contraction looks continuous. That’s why the correct idea is that individual twitches are not discernible. The other options don’t fit: a tremor during contraction implies irregular, oscillating activity rather than a smooth fused contraction; a plateau in force output describes a different pattern where force stops increasing with more stimulation but doesn’t address the visibility of twitches; and a smooth contraction with visible twitches contradicts the idea of completely fused tetanus.

When the stimulation frequency rises, individual motor unit twitches begin to overlap in time and sum up, creating a smooth, sustained contraction known as fused tetanus. At this point the impulses come so fast that you can’t see separate twitches—the contraction looks continuous. That’s why the correct idea is that individual twitches are not discernible. The other options don’t fit: a tremor during contraction implies irregular, oscillating activity rather than a smooth fused contraction; a plateau in force output describes a different pattern where force stops increasing with more stimulation but doesn’t address the visibility of twitches; and a smooth contraction with visible twitches contradicts the idea of completely fused tetanus.