In conventional TENS used for sensory stimulation, what parameter combination is typical?

• A. Low Frequency and Long Phase Duration
• B. High Frequency and Short Phase Duration
• C. High Frequency and Long Phase Duration
• D. Low Frequency and Short Phase Duration

Answer: (C)

Sensory-focused TENS targets the gate-control mechanism by activating the large-diameter Aβ fibers, which modulates pain signals at the spinal cord to produce a comfortable tingling without causing muscle contraction. The way to achieve that is with a high stimulation frequency and a short phase (pulse) duration. High frequency delivers a steady stream of impulses that the patient can feel as paresthesia, while a short pulse width keeps the current amplitude low, so motor fibers aren’t recruited and no visible contraction occurs. This combination—high frequency with a short phase duration—produces effective sensory analgesia with minimal risk of motor response. Typically, you’d see settings in the ballpark of around 50–100 Hz and roughly 50–100 microseconds for the pulse duration. A long phase duration with high frequency would recruit more fibers and could lead to uncomfortable sensations or motor responses, which isn’t desired for purely sensory stimulation.