Burst mode in electrical stimulation is defined as:

• A. A finite series of pulses or a finite interval of AC at a specific frequency flowing for a limited time, followed by no current flow.
• B. Continuous energy at a steady rate.
• C. Random, unpatterned pulses.
• D. A single instantaneous pulse.

Answer: (A)

Burst mode means delivering a short train of pulses at a chosen frequency for a defined duration, then turning the current off for a rest period before the next burst. The key idea is a finite series of pulses or a finite interval of AC with no current flow afterward, rather than continuous stimulation. This pattern contrasts with continuous energy that flows steadily, random or unpatterned pulses that lack a consistent timing, and a single instantaneous pulse which has no repetition. Using bursts can improve comfort and reduce fatigue by interrupting the stimulation with rest periods while still delivering therapeutic effect within each burst.