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.
Study Type
INTERVENTIONAL
Allocation
NON_RANDOMIZED
Purpose
OTHER
Masking
NONE
Enrollment
53
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
CHU de Montpellier
Montpellier, France
CHU de Nîmes
Nîmes, France
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
Time frame: Inclusion
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
Time frame: 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
Time frame: 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
Time frame: 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 \& + ∞)
Time frame: Inclusion
Time since stroke (acute, subacute or chronic phase)
months
Time frame: Inclusion
Intensity of arm deficit
Fugl-Meyer Upper Extremity score ) (score between 0 and 66)
Time frame: 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
Time frame: Inclusion
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