If the intensity is at maximum but contractions are insufficient, which adjustment should be made?

• A. Increase Amplitude
• B. Decrease Pulse Duration
• C. Decrease Frequency
• D. Increase Pulse Duration

Answer: (D)

When intensity is already at its maximum, you can’t push more current through, so the next lever is the amount of energy delivered per pulse. Increasing pulse duration lengthens each pulse, which raises the total charge per pulse (charge = current × duration). More charge recruits additional motor units and strengthens the contraction without needing more current. Shortening the pulse would reduce energy per pulse and weaken contraction; changing frequency changes the timing of pulses and the fusion of contractions but doesn’t add more energy per pulse, and increasing amplitude isn’t an option since the maximum is already reached. So, lengthening the pulse duration is the adjustment to make.