Development and assessment of vibrotactile feedback from the embedded sensors of a microprocessor-controlled knee prosthesis.

The out-of-lab functional assessment was done with only one participant with a transfemoral amputation, and she was already highly able, so the results cannot show what would happen in most patients using a prosthesis. Able-bodied participants walked with a bypass knee, so their perception and comfort may not match people using a fitted prosthetic socket. The participant with amputation used a study C-Leg 4 rather than her usual Rheo Knee, with only a 15-minute familiarization period. Each feedback scheme was tested once in the out-of-lab session, so limited exposure may have reduced learning or adaptation. Gait symmetry changes were modest, and within-trial variability was high during stairs, so some differences may reflect normal fluctuation. Force feedback used an externally placed pressure insole, so its effect cannot be separated from the prosthesis or other parts of the system. The belt placement adds a wearable component outside the prosthesis, so its better perception and comfort may come with practical inconvenience. Comfort, cognitive load, and usefulness ratings were subjective, and the functional part relied on one participant's repeated conditions, not a group comparison.

The article states funding from HORIZON EUROPE Marie Sklodowska-Curie Actions. It does not report author conflicts of interest or a sponsor role in design, analysis, or writing.

Do not read the preference for force feedback as proof that embedded prosthesis sensors improve walking. The functional test used one participant with a transfemoral amputation, force feedback came from an externally placed pressure insole, and gait changes were modest and variable.