Impact of transradial amputation and brachial plexus injury on vibrotactile sensation capacity of the upper extremity.

The study had only five participants with transradial amputation and six with brachial plexus injury, and the authors called it underpowered, exploratory, and mostly qualitative in group comparisons. One participant with brachial plexus injury stopped before the tracking task, so only five are represented in those tracking results. The affected limb was at rest and the joystick was controlled with the unaffected hand, so the tasks do not show how feedback works during real prosthesis control. Phantom hand maps were not assessed systematically, so the study cannot describe how referred phantom sensations relate to vibrotactile perception. All participants with brachial plexus injury had complete C5-Th1 avulsion, but surgical reconstruction and time since injury varied, limiting generalization to other injury patterns. The able-bodied benchmark was taken from a previous study, although it was collected in the same laboratory with the same equipment and experimenter. Only one tactor type and one vibration frequency, 230 Hz, were tested, so perception at other frequencies was not measured.

Funded by Medizinische Hochschule Hannover under grant 3118. The supplied text does not report author conflicts of interest.

Do not conclude that vibrotactile feedback will improve real prosthetic control in these patients. The study tested sensation in a quiet laboratory, with the affected limb at rest and the joystick controlled by the unaffected hand, and it was underpowered.