Stimulation of denervated muscle uses which type of current?

Stimulation of denervated muscle uses which type of current?

• A. Alternating current
• B. Direct current
• C. Pulsed biphasic current
• D. No current

Answer: (B)

When a muscle is denervated, there is no neural input to trigger contraction, so the muscle fibers must be stimulated directly. This requires a long-duration, unidirectional (monophasic) current that directly depolarizes the muscle cell membranes rather than relying on nerve activation. Alternating current or pulsed biphasic current are designed to recruit muscles via nerves or rely on short pulses, which are ineffective for denervated muscle because they don’t provide the sustained direct stimulation the muscle fibers need. No current would yield no contraction at all. Therefore, direct current is the appropriate choice.

When a muscle is denervated, there is no neural input to trigger contraction, so the muscle fibers must be stimulated directly. This requires a long-duration, unidirectional (monophasic) current that directly depolarizes the muscle cell membranes rather than relying on nerve activation. Alternating current or pulsed biphasic current are designed to recruit muscles via nerves or rely on short pulses, which are ineffective for denervated muscle because they don’t provide the sustained direct stimulation the muscle fibers need. No current would yield no contraction at all. Therefore, direct current is the appropriate choice.