Non-use After Stroke: Influence of Applied Force and Precision When Reaching With the Paretic Upper Limb

Study Overview
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Brief Summary
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After a stroke, 80% of patients have an upper limb deficit, limiting activity. Some develop a non-use: they can, but do not, use their paretic limb. Non-use is a general phenomenon applied to all situations where the patient applies unnecessary compensation. Several rehabilitation techniques are effective to counter non-use, but there is insufficient knowledge to choose the most suitable technique. Optimal control theory could help guide these choices. It assumes that the chosen coordination satisfies the constraints of the task (force, amplitude, tolerance) while reducing the cost of the movement. This study will assess non-use by anticipating the sensitivity to the constraints of force and precision deduced from the logic of optimal control. The study authors expect to observe a weakness effect: in a reaching task (i.e. when the person has to touch an object placed in front of them), lightening the paretic arm makes it possible to reduce non-use, and a precision effect: in a reaching task, non-use increases with the required spatial precision.

Official Title
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Non-use après Accident Vasculaire cérébral : Influence de la Force et de la précision du Geste à Fournir Lors Des Mouvements du Membre supérieur parétique

Conditions
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Stroke

Intervention / Treatment
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* Other: Reaching Session


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Inclusion criteria specific to the stroke group: Patient having had a 1st stroke Patient whose stroke occurred more than a month ago. Patient having had a supratentorial stroke Patient able to touch the opposite knee with the paretic arm Inclusion criteria specific to the control group: Subject who has never had a stroke Subject without motor or orthopedic impairment of the upper limbs and in particular of the shoulder General inclusion criteria: Subject who has given free and informed consent. Subject who signed the consent form. Subject affiliated or beneficiary of a health insurance plan. Exclusion criteria: Pregnant, parturient or breastfeeding subject. The subject is participating in a category 1 interventional study, or is in a period of exclusion determined by a previous study The subject refuses to sign the consent It is impossible to give the subject informed information The patient is under safeguard of justice or state guardianship Patient with cognitive disorders incompatible with a good understanding of the use of the device Patient with other neurological or osteoarticular history that may limit the performance of the task - criterion left to the deiscretion of the investigator

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Patients with stroke<br> | Other: Reaching Session<br>* Two x 45 minutes sessions of reaching tasks. Patients in the stroke group will perform the task with the paretic arm using a weight reduction system, allowing movement in the horizontal plane. Subjects in the control group will perform the task with the randomly selected arm weighted at 80% of their maximum voluntary shoulder torque<br>|
| Controls<br> | Other: Reaching Session<br>* Two x 45 minutes sessions of reaching tasks. Patients in the stroke group will perform the task with the paretic arm using a weight reduction system, allowing movement in the horizontal plane. Subjects in the control group will perform the task with the randomly selected arm weighted at 80% of their maximum voluntary shoulder torque<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Evaluate the modifications of the proximal non-use after stroke on the paretic side according to the extent of force constraint | Proximal Arm Non Use (PANU) score (%): A significant PANU (> 7.5%) indicates non-use | Inclusion | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Evaluate the modifications of the proximal non-use after stroke on the paretic side according to the precision required | PANU score (%): Physiological non-use considered as a decrease in PANU due to to the increase in the size of the target; A psychological non-use considered as absence of decrease in PANU, regardless of the condition | Inclusion | 
| Evaluate the modifications of the proximal non-use in the control subjects according to the constraints of force or precision | PANU score (%) of force and precision | Inclusion | 
| Evaluate the level of neuromuscular activation during reaching | % Voluntary Maximum Contraction (VMC) of anterior and intermediate part of the deltoid, biceps brachii and pectoralis major | Inclusion | 
| Model the constraints and costs explaining non-use patient by patient, to distinguish between physiological and psycho-behavioral non-use | Weight-over-force ratio of the arm (Ratio between 0 & + ∞) | Inclusion | 
| Time since stroke (acute, subacute or chronic phase) | months | Inclusion | 
| Intensity of arm deficit | Fugl-Meyer Upper Extremity score ) (score between 0 and 66) | Inclusion | 
| height of the target | Evaluate changes in the proximal non-use after stroke on the paretic side according to the height of the target to be reached with PANU score (%) : A significant PANU (> 7.5%) indicates non-use | Inclusion | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Non-use, Compensation, Weakness, Optimal control