Postural Responses to External Perturbation in Post-Stroke

Study Overview
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Brief Summary
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To maintain stable body balance in daily activities, the ability to respond to external perturbations is an essential factor. Such capacity is limited in pathological conditions, such as in stroke, in which postural control is impaired due to lesions to the central nervous system. Impairment to postural control increases body sway during upright posture and leads to augmented frequency of falls. In this sense, the identification of mechanisms involved in body balance disorders after stroke is particularly important in situations of postural perturbation. The purpose of this project is to evaluate reactive postural responses to unpredictable external perturbations, analyzing postural dysfunctions caused by lesion to different brain areas as a result of stroke, and test principles of dynamic body balance rehabilitation.

Official Title
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Postural Responses to External Perturbation in Post-Stroke: Sensorimotor Integration and Rehabilitation

Conditions
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Stroke

Intervention / Treatment
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* Other: Sensory Intervention


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Inclusion criteria are as follows. Healthy participants: absence of detectable neurological or physical malfunction which might affect postural control, no use of drugs affecting body balance and preserved mental capacity. Stroke patients: capacity to sustain independently orthostatic posture for at least 5 min. and preserved mental capacity. Exclusion Criteria: Exclusion Criteria are: no orthopedic malfunction, no clinical instability associated with systemic disease, no use of drugs affecting body balance and presence of pusher syndrome.

Ages Eligible for Study
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Minimum Age: 45 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Sensory Conditions<br> | Other: Sensory Intervention<br>* full sensory information, whose participants will practice balancing tasks without constraint sensory body; sensory constraint, whose participants will practice the same balance tasks with constraint body of visual and tactile information from the soles of the feet; control, whose participants will exercise activities involving cognitive and upper limbs.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Displacement amplitude of the CP to the anterior-posterior and medial-lateral | This outcome measure quantified by the difference between the maximum values of the anterior-posterior and medial-lateral after the start of trial and average position in the axis anteroposterior and mediolateral, respectively, in the 200 ms prior to the onset of the trial. | 2 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Coordination between the hip and ankle joint | Coordination between the hip and ankle joints, which is evaluated by adjusting the angle displacement data, hip and ankle angle within 95% of an ellipse surrounding the values of the disturbance moment until the end of the trial. Will be carried out a regression analysis to identify the slope of the fitted ellipse. Slopes greater indicate a greater share of the ankle in relation to the hip | 2 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Cerebrovascular Accident, Rehabilitation, Sensory System