What is a good on/off ratio for a person with radial nerve palsy when using NMES?

What is a good on/off ratio for a person with radial nerve palsy when using NMES?

• A. 1:1
• B. 1:3
• C. 3:1
• D. 1:5

Answer: (B)

The key idea is using a duty cycle that minimizes fatigue while still providing meaningful muscle activation. For radial nerve palsy, the forearm extensors are recovering and tend to tire quickly with electrical stimulation, so giving the muscle time to recover between contractions is important. An on/off ratio of 1:3 means the muscle contracts briefly and then rests longer (for example, 1 second on, 3 seconds off). This shorter activation with longer recovery helps prevent rapid fatigue, allows better re-oxygenation, and reduces cramping or discomfort, which supports sustained therapy sessions and functional retraining of wrist and finger extension. Ratios with more on time (like 1:1 or 3:1) would fatigue the muscle faster, while an even longer off time (such as 1:5) might under-stimulate and slow progress. So 1:3 strikes a practical balance for this scenario.

The key idea is using a duty cycle that minimizes fatigue while still providing meaningful muscle activation. For radial nerve palsy, the forearm extensors are recovering and tend to tire quickly with electrical stimulation, so giving the muscle time to recover between contractions is important. An on/off ratio of 1:3 means the muscle contracts briefly and then rests longer (for example, 1 second on, 3 seconds off). This shorter activation with longer recovery helps prevent rapid fatigue, allows better re-oxygenation, and reduces cramping or discomfort, which supports sustained therapy sessions and functional retraining of wrist and finger extension. Ratios with more on time (like 1:1 or 3:1) would fatigue the muscle faster, while an even longer off time (such as 1:5) might under-stimulate and slow progress. So 1:3 strikes a practical balance for this scenario.