Moving a missing hand: children born with below elbow deficiency can enact hand grasp patterns with their residual muscles.

Only six participants aged 6–20 years were tested, and the analysis was done child by child, so the paper does not support group-level conclusions. The study tested ultrasound muscle patterns in a laboratory, not a prosthesis, not daily activities, and not clinical outcomes. Trial numbers were low and variable, and the acceptable accuracy threshold was set at 80%, lower than the 85% often used for adults. The children had no training in mimicking hand motions with the affected limb, so this is a baseline motor assessment rather than a device-control training result. The authors note that muscle states may not have the same meaning as cortical representation of a missing hand. Participants were highly heterogeneous, which the authors say limits group-level inference and makes cross-child comparison difficult.

The supplied text lists funding from the National Center for Advancing Translational Sciences and the National Science Foundation. It does not include an author conflict-of-interest declaration.

Do not conclude that ultrasound-controlled prostheses improve daily function or that these children are ready for advanced device control. This was a laboratory study of six children with no prosthesis use, no training, and no clinical outcomes.