1. To characterize compensatory balance reactions to platform translations during standing and walking in poststroke individuals in comparison to healthy individuals.
2. To explore the effect of lesion characteristics (location, size) on the patients' balance reactions.
3. To explore the impact of clinical measures of unilateral sensory motor impairments, balance, gait and fear of falling on postural reactions in stroke subjects.
4. To examine the effect of a perturbation-based balance training on balance reaction characteristics in post stroke individuals.
Study design: Two stage study. Stage 1 - examination, stage 2 - intervention. stage 1: 60 post-stroke subjects will be recruited from rehabilitation units at Loewenstein hospital, Raanana, Israel. 60 healthy age-matched controls will be recruited by snowball sampling method from the physical therapy department and will be matched as close as possible for gender and BMI.The following measurements will be administered:
1)Compensatory balance reaction measurement:
Compensatory balance reactions will be measured using the BalanceTutor (MediTouch). The BalanceTutor is a mechatronic device consisting of a computerized treadmill with a horizontal movable platform and an operator station. Measurements will be taken in two conditions:
Standing. Subjects will be instructed to stand and will be exposed to random unexpected platform translations. The platform translations will be increased systematically and controlled. The increases in platform translation will be adjusted by the examiner to the subject's ability to recover from perturbations. Participants will be asked to respond in a "natural" manner to perturbations.
Walking. Subjects will be instructed to walk comfortably (self-paced) on the treadmill, and will be exposed to random unexpected platform translations. The platform translations will be increased systematically and controlled and will be adjusted by the examiner to the subject's ability to recover from perturbations. Compensatory balance reaction characteristics (reaction time, swing time, compensatory step time, step length etc.) will be collected through a three-dimensional motion analysis system. During examination subjects will wear a loose safety harness that will prevent a fall and yet allow the execution of balance recovery reactions.
In addition, clinical measures will be used: Berg Balance Scale, 6 minute walk test, 10 meter walk test, the Fugl-Meyer test for motor recovery after stroke and the ABC (Activities-specific Balance Confidence) scale. Normalized lesion data will be computed using the ABLE module within MEDx software (Medical Numerics).
Stage 2 - 60 stroke subjects from the neurology rehabilitation unit at Loewenstein hospital will be randomly allocated to one of two groups: 1) perturbations based balance training 2) Balance and gait training without external perturbations (control).
Group 1 - Perturbations based balance training Subjects will complete a perturbation based balance training while standing and walking on the BalanceTutor (MediTouch). Perturbation level will be individually adjusted and progressed according to subject's abilities. Progression occurs by increasing perturbation level (increase distance, velocity and acceleration). At each practiced level subjects will be exposed to random right/left/forward/backward unannounced platform translations while standing and to right/left perturbations (in defined events in gait cycle) while walking. In order to examine adaptation to repeated perturbations, kinematic data will be collected in the first session.
Group 2 - Balance and gait training without external perturbations (control) Subjects will complete a balance training program that includes voluntary weight shifting while standing on a computerized posturography (NeuroCom) and walking on a treadmill. Weight shifting toward a target will be adjusted and progressed according to subject's abilities. Progression in difficulty level will occur by increasing the distance to target without changing the base of support. At each practiced level weight shifting will be conducted to right/left/forward/backward directions. In the gait part of the session, subjects will be asked to walk at their preferred treadmill walking speed.
Subjects in both groups will complete 10-12 training sessions, 4-5 per week for 3 weeks. Each session will last 30 minutes and will include practice in standing and walking. Subject's activities will be documented in each session in both groups. Furthermore, in each session subjects will be asked to rate their perceived level of challenge on a 0-10 scale.
In addition to training sessions pre- and post-intervention measurements as in stage 1 will be conducted. In addition, an accelerometer will be placed with a sticker on the subject's thigh for recording 24-48 hour activities. A follow-up measurement will be conducted 3-6 weeks post intervention.
- BalanceTutor Device
ARM 1: Kind: Experimental Label: BalanceTutor
- Posturograph Device
ARM 1: Kind: Experimental Label: Posturograph Description: Balance and gait training without external perturbations. Voluntary weight shifting while standing on a computerized posturography (NeuroCom) and walking on a treadmill. 10-12 training sessions, 4-5 per week for 3 weeks. Each session will last 30 minutes.
- Masking: Open Label
- Purpose: Treatment
- Intervention: Single Group Assignment
|Type||Measure||Time Frame||Safety Issue|
|Primary||compensatory step execution time pre intervention||1-5 days before the first session of intervention||No|
|Primary||compensatory step execution time post intervention||1-5 days after the last session of intervention||No|
|Secondary||Berg Balance Scale score pre intervention||1-5 days before the first session of intervention||No|
|Secondary||Berg Balance Scale score post intervention||1-5 days after the last session of intervention||No|
|Primary||change in compensatory step execution time||1-5 days before the first session of intervention and 1-5 days after the last session of intervention.|
|Primary||change in compensatory step velocity||1-5 days before the first session of intervention and 1-5 days after the last session of intervention.|
|Secondary||change in Berg Balance Scale score||1-5 days before the first session of intervention and 1-5 days after the last session of intervention.|
|Secondary||change in fall threshold|