The Effect of Perturbration on Balance Control in Adults

Study Overview
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Brief Summary
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Balance control in respond to an unexpected platform perturbration during standing and walking: comparison between individuals with chronic ankle instability and healthy individuals.

Detailed Description
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An unexpected postural perturbration is a major risk factor of falls and injuries during gait. A postural perturbration is a sudden change in conditions that displaces the body posture away from equilibrium. Reactive postural control response is an immediate ( 70-120 ms ) automatic like reflex response which is initiated by unexpected postural perturbration in order to maintain balance. Even among young healthy adults there could be a problem in balance performance which does not become evident untill a slip or a trip or any other sudden perturbration happens. Thus a simple test of pertubration while standing or walking can identify a problem . This study is comparing the reactive postural control of physical education students who suffer from chronic ankle instability (CAI) to healthy students on a Perturbation Treadmill. The device consists of a treadmill mounted on a moving force plate platform. The platform moves in the medial/ lateral plains to simulate a slip and a trip in both the standing and walking phase. Their reactive postural control is tested in a few conditions: standing on both legs - eyes open and eyes closed, in tandem standing, standing on one leg and in walking. In each condition the perturbration is given every 5-15 seconds in different speed and in unexpected direction (right /left). Lost of balance control is any change in the original location of the foot in standing conditions or stepping out of the treadmill.

Official Title
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The Effect of Perturbration on Balance Control in Adults

Conditions
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Chronic Ankle Instability

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: age 18-50 good health active people Exclusion Criteria: Body weight greater than 135 kg Bone instability (non-consolidated fractures, unstable spinal column, severe osteoporosis) Head damage in the year prior to the study Diabetics or Unstable circulation Cardiac (blood) contraindications Vestibular problem Neurological deficits Mechanical ventilation problem Severe vascular disorders of the lower limbs

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 50 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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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| static balance control in reaction to perturbration | The angle velocity at the ankle at the moment of loosing postural control while standing | 20 minutes | 
| dynamic balance control un reaction to perturbration | the speed of perturbration at the moment of loosing balance while walking | 10 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Time to returning to original condition | How much time it takes to come back to the original step (Center of Pressure - COP) after the perturbration | 30 minutes | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Chronic ankle instability ( CAI ), Perturbration, reactive postural control, balance, center of pressure - COP