Does electrical stimulation synchronized with ankle movements better improve ankle proprioception and gait kinematics in chronic stroke? A randomized controlled study.

The groups ended up very unequal. Five of the 17 people in the control group dropped out, leaving 12, and the authors say the results may be biased in favour of the movement-plus-stimulation group. The study was small, 30 people completed it, and it took place in a single rehabilitation hospital. No balance, walking or function measure differed between the two groups, so it is not known whether the measured ankle changes translate into anything a patient or family would notice. Everyone in the study could already walk (a walking ability score of at least 3 out of 5), so the results say nothing about patients who cannot walk. Nobody was assessed after the 4 weeks finished, so the longer-term effect is unknown. The proprioception test requires remembering a target angle, and the authors say memory problems, ankle muscle fatigue and small movement errors they could not detect may have affected the results. The authors suggest the intensity and duration of the training may simply have been insufficient. The authors could not rule out that participants got better at the tests through repeated assessment.

Funded by the Translational Research Project for Rehabilitation Robots at the Korea National Rehabilitation Center, Ministry of Health & Welfare, South Korea, through two grants (2018 and 2022). The authors declare no conflicts of interest. The paper does not state whether the funder had any role in designing the study or writing it up.

Do not take this as evidence that timing electrical stimulation to ankle movement restores ankle proprioception. Proprioception did not improve significantly in either group, even though that was the question in the title. Nor did any balance, walking or function measure differ between the two groups, so the within-group gains in walking speed, balance and step length cannot be credited to the movement-synchronized stimulation.