Improving interlimb coordination and paretic limb use after stroke using a novel robotic split-crank pedaling device: a cross-sectional study.

The study only examined within-session effects with very brief exposures (3 minutes per scheme). It is unknown if longer training periods would lead to retention or carryover. Participants were relatively well-recovered for a stroke population (mean Fugl-Meyer lower extremity score of 80/96), so findings may not generalize to more severely impaired individuals. Net mechanical work data were missing for 5 of the 19 stroke participants due to technical issues. Two stroke participants could not complete the Resist (R) scheme at the minimum gain, limiting the sample size for that specific condition. The rebound effect (worse-than-baseline errors post-exposure) suggests the device may induce maladaptive reliance or slacking, which was not mitigated by the current protocols.

Funding was provided by the National Center for Medical Rehabilitation Research, the National Center for Advancing Translational Sciences, the Advancing Healthier Wisconsin Endowment, and the Rev. John P. Raynor, SJ Fellowship. No conflicts of interest were declared by the authors.

Do not interpret the reduction in phasing error during exposure as evidence of motor learning or functional improvement. The error rebounded to worse-than-baseline levels immediately after the device was turned off, indicating that the effect was purely mechanical assistance or temporary adaptation, not a lasting change in the patient's ability to coordinate their limbs.