What would be a typical electrode configuration for treating knee osteoarthritis with NMES?

• A. One pair of electrodes over the quadriceps motor points to promote knee extension, with separate return electrodes placed proximally or distally
• B. Electrodes placed on the hamstrings to encourage knee flexion only
• C. Electrodes placed around the ankle
• D. A single electrode over the patella

Answer: (A)

Aiming to strengthen the knee in knee osteoarthritis, the most effective NMES setup is to activate the quadriceps to drive knee extension. This is achieved by placing two active electrodes over the quadriceps motor points so the current reliably stimulates the quadriceps muscles, promoting a knee- extending contraction. A separate return electrode is placed either proximally or distally on the thigh to complete the electrical circuit and help direct the current through the desired muscle group. This configuration targets the muscle group that provides knee extension and joint stability, which is key for improving gait and function.

Electrodes on the hamstrings would encourage knee flexion, not the extension needed here. Placing electrodes around the ankle targets distal muscles and won’t produce a strong, functional knee extension. A single electrode over the patella wouldn’t create an effective current path or consistent muscle recruitment.