Proprioceptive-augmented virtual reality influences the kinematic properties of movement imitation.

All 23 participants were healthy adults aged 18 to 40, so nothing here shows what would happen in people with neurological damage, which is the group this kind of treatment is meant for. Only five trials per condition and task in a single session. The study measured immediate performance, not learning, and did not check whether any change lasted. Only one simple movement was studied, elbow bending and straightening. Whether the same pattern holds for the multi-joint actions of daily life is unknown. There was no comparison condition using vibration that does not produce an illusion of movement, so a general effect of touch, vibration or attention cannot be separated from the specific effect of the movement illusion. Participants rated how vivid the illusion felt only after the OFFLINE task, and did not complete the embodiment questionnaire after the ONLINE task, so the two tasks cannot be compared on either measure. The authors describe the study themselves as a proof-of-concept first step towards more complex designs.

The work was funded by the European Union's NextGenerationEU programme. The vibration devices were custom-designed by a commercial company, Ermit srl (Genoa, Italy), which also ran the preliminary bench tests confirming the vibration frequency. No other funding source or competing interest is reported in the text.

Do not read this as evidence that tendon vibration improves movement imitation. It only helped in the task where people copied the movement after watching. In the task where they moved while watching, the same vibration made reproduction significantly worse on every measure. The participants were healthy young adults doing a short lab task, not patients in therapy.