Which waveform is used to facilitate wrist extension for self-feeding?

• A. EMS-A for two groups of muscles (extension and flexion) for self feeding
• B. EMS-D for single group
• C. EMS-C for wrist extension
• D. EMS-S for 1 group of muscles (extension)

Answer: (D)

To perform a functional task like self-feeding, the goal is to produce the needed movement by stimulating only the muscle group responsible for that movement. For wrist extension, that means activating the wrist extensor muscles without also triggering the flexors. A single-group waveform provides current to just one muscle group, yielding isolated wrist extension. This targeted approach gives more precise control, smoother motion, and reduces unwanted co-activation of opposing muscles, which is crucial for reliably reaching and positioning the hand to bring food to the mouth.

Stimulating two muscle groups (extension and flexion) would create competing actions and less predictable movement, making it harder to achieve the desired wrist position. While others might claim extension, they don't offer the same level of isolation and control as the single-group approach, which is why the single-group waveform is the best choice for facilitating wrist extension during self-feeding.