Neuromechanics of nonuse and compensation: implications for rehabilitation after stroke

 

The idiotic idea than learned nonuse exists is still around. 

 I absolutely hate these pontifications on nonuse. Solve the damn problem of dead brain rehab and this nonuse problem goes away. SOLVE THE CORRECT PROBLEM!

Damn it all, it is NOT learned nonuse. It is the actual inability to use it because of dead neurons. If you had dead brain rehab protocols, this fake learned nonuse idea would cease to exist!

Neuromechanics of nonuse and compensation: implications for rehabilitation after stroke

View ORCID ProfileGermain Faity

, View ORCID ProfileDenis Mottet,  View ORCID ProfileJérôme Froger, Marion Delorme

doi: https://doi.org/10.1101/2025.09.11.25335554

This article is a preprint and has not been peer-reviewed [what does this mean?]. It reports new medical research that has yet to be evaluated and so should not be used to guide clinical practice.

Abstract

Stroke often results in compensatory movement strategies that combine use of trunk movements with nonuse of the affected upper extremity, which is considered detrimental to recovery. In this study, we investigate whether compensation and nonuse can be more than a suboptimal counterpart to recovery. We explore the influence of neuromechanics on nonuse and compensation in 22 stroke survivors and 22 controls. We asked seated participants to reach a target under two nonuse conditions (spontaneous or with minimized trunk compensation) and under three arm weight conditions (control, lightened and weighted). We replicated the findings that stroke induces more trunk compensation, more anterior deltoid activation and greater effort. We found that, in stroke patients, reduced arm weight decreased nonuse, while in controls, increased arm weight induced trunk compensation similar to what is observed after stroke. Furthermore, reaching with nonuse after stroke required less effort and preserved a force reserve at the shoulder. Our results show that both poststroke and healthy individuals engage in similar nonuse and compensation in the face of their neuromechanical limitations, as predicted by an optimal control policy aiming to succeed at the task while keeping a force reserve at each joint. We derive two theoretical predictions for future clinical research. First, patients whose nonuse yields few functional gains should benefit most from interventions to reduce compensation. Second, improving shoulder strength after stroke should reduce relative muscle activation, thereby decreasing trunk compensation and upper extremity nonuse. Clinical Trial: NCT047475871 

Competing Interest Statement

The authors have declared no competing interest.

Clinical Trial

NCT04747587

Funding Statement

This study was supported by Nimes University Hospital (ID-RCB: 2020-A02695-34) and the LabEx NUMEV (ANR-10-LABX-0020) within the I-SITE MUSE.

Author Declarations

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Yes

The details of the IRB/oversight body that provided approval or exemption for the research described.