Myocontrol is closed-loop control: incidental feedback is sufficient for scaling the prosthesis force in routine grasping.

The study included 10 able-bodied people who had never used a prosthesis, so it does not show how experienced people with amputation perform. All testing was done in a quiet lab with the prosthesis visible and the same object grasped repeatedly, which may make incidental cues easier to use than in daily life. The tasks were presented in a fixed order that increased feedback, so performance differences are partly tied to that sequence. Levels 2 and 6 were excluded from error analysis because level 6 saturated and level 2 used the prosthesis minimum-force coupling, so extremes are not captured. The prosthesis could not reduce force after contact, so explicit force feedback was used between trials, not within a grasp. The explicit feedback was an ideal continuous visual force display, which may not resemble usable feedback in a real prosthesis.

Funding was from the European Commission and BMBF; no author conflicts of interest are stated.

Do not conclude that explicit force feedback is unnecessary for people with amputation who use myoelectric prostheses. The study used 10 able-bodied people in a quiet lab, and explicit visual force feedback still significantly improved command accuracy and force accuracy at higher target levels.