Which statement best differentiates NMES from conventional TENS?

• A. NMES aims to modulate pain by stimulating sensory nerves without strong contractions
• B. NMES aims to produce purposeful muscle contractions for strength, motor control, or functional tasks; TENS aims to modulate pain without strong contractions
• C. NMES uses DC exclusively; TENS uses AC
• D. NMES aims to cause muscle fatigue

Answer: (B)

The key idea is the purpose behind the electrical stimulation. NMES is used to provoke purposeful muscle contractions to build strength, improve motor control, or enable functional tasks, by stimulating motor nerves to cause visible contractions. Conventional TENS, by contrast, is aimed at modulating pain and typically uses settings that target sensory fibers, providing analgesia with little or no strong muscle contraction. So the statement that NMES aims to produce purposeful muscle contractions for strength and function, while TENS aims to modulate pain without strong contractions, best captures how these modalities differ. Some TENS protocols can cause minor contractions, but the primary goal of TENS is pain relief, not muscle strengthening.