Brief-intense TENS is characterized by what parameters and primary risk?

• A. Low frequency; long pulse durations; low amplitude; risk of skin irritation.
• B. Medium frequency; medium pulse durations; risk of numbness.
• C. Direct current with constant flow; risk of burns.
• D. High frequency ~100-200 Hz, short pulse durations ~150-250 μs, high amplitude to elicit a motor response; risk of discomfort or muscle contraction.

Answer: (D)

Brief-intense TENS is defined by delivering rapid, very short electrical pulses at a relatively high amplitude so the stimulation can provoke a motor response. The frequency is typically high (around 100 to 200 Hz), and the pulse duration is short (about 150 to 250 microseconds). Because the amplitude is raised to produce a noticeable motor response, the main risk is discomfort or an observable muscle contraction. This contrasts with other modes that use longer pulses or lower amplitudes and carry different sensations and risks. When used properly, brief-intense aims for strong but brief activation, and the key safety note is to monitor comfort and reduce intensity if necessary.