Transcutaneous spinal stimulation with upper extremity robotic training in chronic stroke and spinal cord injury: individual neurophysiological and clinical responses.

Eleven participants were analysed, and the study was exploratory, so group-level conclusions are weak. No formal hypothesis testing or inferential statistics were performed because of the small sample size. All participants received sham before active stimulation, so the order was not randomized and outcome assessors could not be blinded. Participants may have known whether they were receiving active stimulation because sham stimulation was brief. Cervical TSS, robotic training, and hand grip training were delivered together, so the contribution of any single component cannot be separated. Stimulation intensity was often adjusted for comfort, so not every participant reached the intended motor threshold. The exoskeleton did not include a hand or finger module, so hand training was separate and may not translate to complex arm use. Functional scores were ordinal and may miss subtle changes in people with severe chronic arm impairment.

Funding was named as NeuroSpark Seed Funding Program, Craig H. Neilsen Foundation, and National Institutes of Health. The supplied text does not provide an author conflict-of-interest disclosure or state whether funders designed, analysed, or wrote the study.

Do not read the individual improvements as proof that cervical TSS caused them. The participants received robotic training and hand grip training together with stimulation, the phases were not randomized, and blinding was limited, so the effect of any single component cannot be separated.