Postural Responses to External Perturbation in Post-Stroke
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ClinicalTrials.gov Identifier: NCT01912794
Recruitment Status : Unknown
Verified July 2013 by Alessandra Rezende Martinelli, University of Sao Paulo. Recruitment status was: Not yet recruiting
First Posted : July 31, 2013
Last Update Posted : August 1, 2013
University of Sao Paulo
Information provided by (Responsible Party):
Alessandra Rezende Martinelli, University of Sao Paulo
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.
Displacement amplitude of the CP to the anterior-posterior and medial-lateral [ Time Frame: 2 months ]
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.
Secondary Outcome Measures :
Coordination between the hip and ankle joint [ Time Frame: 2 months ]
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
Other Outcome Measures:
Muscle activation latency [ Time Frame: 2 months ]
This outcome measure is time between the time of release and the first load value 3 standard deviations above the mean magnitude in the 200 ms prior to postural disturbance, with subsequent values increasing.
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Ages Eligible for Study:
45 Years to 70 Years (Adult, Senior)
Sexes Eligible for Study:
Accepts Healthy Volunteers:
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 are: no orthopedic malfunction, no clinical instability associated with systemic disease, no use of drugs affecting body balance and presence of "pusher syndrome".