A disadvantage of hybrid prostheses is that

• A. No harness required for elbow operation
• B. Harness is required for elbow operation
• C. It reduces weight
• D. Operates with no force needed

Answer: (B)

Hybrid prostheses mix body-powered control with electric actuation to try to provide both intuitive operation and reduced effort. A key drawback is that elbow movement often still relies on a harness to function. Wearing and adjusting the harness adds bulk, can make donning and doffing more cumbersome, and may cause skin irritation or discomfort during extended use. Because the elbow control depends on this harness (and the associated input), you don’t get a completely hands-free or effortless elbow operation. The other statements describe benefits that aren’t characteristics of this disadvantage: the device isn’t necessarily lighter in all designs, and it doesn’t operate without any force input.