For NMES aimed at strengthening, what electrode placement is commonly used to recruit the quadriceps?

• A. One electrode on the gluteus maximus region; the other on the hamstrings.
• B. One electrode on the patellar tendon and the other on the tibial tuberosity.
• C. Both electrodes over the hamstring region.
• D. One electrode over the motor point of the vastus medialis–vastus lateralis region and the other over the rectus femoris region to produce knee extension.

Answer: (D)

The main idea is to place the electrical stimulation so it drives the quadriceps as a group to extend the knee. For strengthening the quadriceps with NMES, you want the current to flow through the quad muscle heads. Positioning one electrode over the motor point in the vastus medialis–vastus lateralis area and the other over the rectus femoris region targets the primary knee extensors, creating a knee-extension contraction when the current pulses. This setup activates the quadriceps efficiently and in a way that recruits multiple heads, which is important for strengthening.

Placing electrodes on the gluteal region and hamstrings would bias toward hip extension or knee flexion rather than knee extension. Having both electrodes over the hamstrings largely stimulates knee flexion rather than quad-driven extension. Stimulation near the patellar tendon and tibial tuberosity doesn’t reliably recruit the quadriceps in a way that produces a strong, functional knee extension. The quad-focused arrangement across the rectus femoris and the vastus heads is the most effective way to elicit the desired knee-extension contraction.