Neurophysiological Changes After Perturbation-based Training in Older Adults
- Conditions
- Healthy SubjectsPostural BalanceFalling
- Interventions
- Behavioral: Perturbation-based balance training (PBT)Behavioral: Active control (control)
- Registration Number
- NCT06573658
- Lead Sponsor
- The Hong Kong Polytechnic University
- Brief Summary
This is an assessor-blinded neurophysiological study. Participants will be randomly assigned to perturbation-based training (PBT) or active control. Neurophysiological changes in the brain following PBT compared to control will be investigated.
- Detailed Description
A total of 88 participants will be randomly assigned to two groups receiving perturbation-based training (PBT) or active control. Written informed consent will be obtained from participants before baseline assessment. The study will be reported and conducted in line with the CONSORT statement. Participants will be recruited via convenient sampling in the local community. Both groups will receive two sessions of treadmill walking at their comfortable speed. Perturbations will be induced during the treadmill walking only for the PBT group. As informed from previous literature, two sessions of PBT could have improved postural stability for up to 1.5 years. Between-group differences in behavioral and MRI findings will be examined before and after training to identify training-induced changes in postural stability and structures and functional connectivities in the brain. Retention of the changes in the postural stability will be assessed four months after the training period. Incidents of falls will be followed up for 12 months after training.
Recruitment & Eligibility
- Status
- RECRUITING
- Sex
- All
- Target Recruitment
- 88
- Aged ≥ 60 years old
- Community-dwelling
- Right-handed
- Able to communicate effectively in Cantonese or Mandarin
- Able to walk independently on level ground for ≥ 30 minutes
- Abbreviated Mental Test (Hong Kong version) score ≥ 6
- Metal implants (e.g. pacemaker, artificial cochlea)
- Uncorrected vision or hearing impairment
- Osteoporosis
- Hip or knee replacement within the last year
- Musculoskeletal, cardiovascular, mental, or neurological disorders (such as Parkinson's disease) which can affect MRI examination, balance control, or exercise participation.
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Arm && Interventions
Group Intervention Description Perturbation-based balance training group Perturbation-based balance training (PBT) This group will receive two sessions of treadmill walking at their comfortable speed involving perturbations Active control Active control (control) This group will receive two sessions of treadmill walking at their comfortable speed involving no perturbations
- Primary Outcome Measures
Name Time Method Brain connectivity derived from the correlation between the Blood-oxygen-level-dependent (BOLD) signals from different brain regions in arbitrary units obtained during functional MRI pre-intervention, and immediately after the intervention BOLD signal reflecting the brain connectivity during rest will be taken through resting-state functional MRI, during which subjects are instructed to relax with eyes open, to let their mind wander, and not think of anything specific. The regions of interest include the cerebellum, basal ganglia, thalamus, hippocampus, inferior parietal cortex, occipital and frontal lobe.
Gray matter density in arbitrary units by structural Magnetic Resonance Imaging pre-intervention, and immediately after the intervention Gray matter density at cortical and subcortical regions will be taken by structural MRI. The regions of interest include the cerebellum, basal ganglia, thalamus, hippocampus, inferior parietal cortex, occipital and frontal lobe.
- Secondary Outcome Measures
Name Time Method Step time of the recovery steps in milliseconds (ms) pre-intervention, immediately after the intervention, 1 week after intervention and 4 months after intervention Step time of the recovery steps after the perturbation will be traced by the motion capture system synchronized with the force plates embedded underneath the slip-treadmill belts.
Hip height in millimeters (mm) pre-intervention, immediately after the intervention, 1 week after intervention and 4 months after intervention Hip height at the recovery steps after the perturbation will be calculated as the vertical distance from the ground to the midpoint of bilateral hips and normalized by the subjects' height. The positions of bilateral hips will be traced by the motion capture system synchronized with the force plates embedded underneath the slip-treadmill belts.
Balance confidence pre-intervention, immediately after the intervention, 1 week after intervention and 4 months after intervention, and at the last prospective fall follow-up Balance confidence will be measured with the Chinese version of the shortened version of Activities-Specific Balance Confidence Scale (ABC-6). The scale value is from 0 to 100, with higher values representing higher balance confidence.
Postural stability pre-intervention, immediately after the intervention, 1 week after intervention and 4 months after intervention Postural stability at the recovery steps after the perturbation will be calculated as the distance between the absolute CoM position in an anteroposterior direction relative to the closest edge of Base of Support (BoS) and normalized by foot length.
The absolute CoM position and BoS position will be traced by the motion capture system synchronized with the force plates embedded underneath the slip-treadmill belts.Responsive postural adjustment upon translation pre-intervention, immediately after the intervention, 1 week after intervention and 4 months after intervention Responsive postural adjustment upon translation will be assessed through Motor Control Test on a computerized dynamic posturography (Bertec® Balance Advantage® Dynamic System, Bertec® Corporation, Columbus, USA). During the Motor Control Test, participants will be requested to maintain their standing balance in response to 18 translations of the standing platform in either forward or backward direction with small, medium or large amplitudes. Weight symmetry, latency of reaction, and amplitude of sway will be recorded. Full-body safety harness will be worn throughout the tests to protect the participants from any potential loss of balance.
Step length of the recovery steps in millimeters (mm) pre-intervention, immediately after the intervention, 1 week after intervention and 4 months after intervention Step length of the recovery steps after the perturbation will be traced by the motion capture system synchronized with the force plates embedded underneath the slip-treadmill belts.
Gray matter volume in cubic millimeters (mm³) by structural Magnetic Resonance Imaging (MRI) pre-intervention, and immediately after the intervention Gray matter volume at cortical and subcortical regions will be measured by Structural MRI. The regions of interest include the cerebellum, basal ganglia, thalamus, hippocampus, inferior parietal cortex, occipital and frontal lobe.
Number of laboratory-falls pre-intervention, immediately after the intervention, 1 week after intervention and 4 months after intervention The number of laboratory-falls following perturbation during assessment sessions will be recorded. A fall will be defined if there is a body-weight support of 30% or more from the full-body safety harness.
Muscle activation onset latency in milliseconds pre-intervention, immediately after the intervention, 1 week after intervention and 4 months after intervention Muscle latency will be collected from trunk and leg muscles using electromyography.
Cognitive flexibility and executive function pre-intervention, immediately after the intervention, 1 week after intervention, and 4 months after intervention Cognitive flexibility and executive function assessed by Trial Making Tests A and B (in the unit of seconds)
Number of real-life-falls 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, and 12 months after the intervention. The number of real-life falls in 12 months after randomization will be recorded. Fall circumstances and related injuries will be enquired via phone contact. A fall is defined as an event resulting in a person unintentionally coming to rest on the ground or other lower level, not as the result of a major intrinsic event e.g., syncope, stroke, seizure, or overwhelming hazard such as an earthquake.
Trunk angle pre-intervention, immediately after the intervention, 1 week after intervention and 4 months after intervention The trunk angle at the recovery steps after the perturbation will be calculated as the angle between the trunk segment with the vertical line. The position of the trunk will be traced by the motion capture system synchronized with the force plates embedded underneath the slip-treadmill belts.
Responsive postural adjustment upon tilting pre-intervention, immediately after the intervention, 1 week after intervention and 4 months after intervention Responsive postural adjustment upon tilting will be assessed through Adaptation Test on a computerized dynamic posturography (Bertec® Balance Advantage® Dynamic System, Bertec® Corporation, Columbus, USA). During the Adaptation Test, the force platform will either tilt up or down for a total of 10 repetitions. Sway energy will be recorded. Full-body safety harness will be worn throughout the tests to protect the participants from any potential loss of balance.
Dynamic balance pre-intervention, immediately after the intervention, 1 week after intervention, and 4 months after intervention Dynamic balance will be assessed by Alternate Step Test (in the unit of seconds)
White matter volume in cubic millimeters (mm³) by structural Magnetic Resonance Imaging (MRI) pre-intervention, and immediately after the intervention White matter volume at cortical and subcortical regions will be measured by Structural MRI. The regions of interest include the cerebellum, basal ganglia, thalamus, hippocampus, inferior parietal cortex, occipital and frontal lobe.
Mean diffusivity measures in mm²/s by Diffusion Tensor Imaging pre-intervention, and immediately after the intervention Mean diffusivity will be derived from the diffusion tensor. The regions of interest include the cerebellum, basal ganglia, thalamus, hippocampus, inferior parietal cortex, occipital and frontal lobe.
Functional lower body strength pre-intervention, immediately after the intervention, 1 week after intervention, and 4 months after intervention Functional lower body strength will be assessed by Five-time Sit to Stand Test (in the unit of seconds)
Mobility pre-intervention, immediately after the intervention, 1 week after intervention, and 4 months after intervention Mobility will be assessed by Timed Up and Go test (in the unit of seconds).
Cortical thickness in mm measured by structural Magnetic Resonance Imaging pre-intervention, and immediately after the intervention Cortical thickness in mm measured by structural MRI. The regions of interest include the cerebellar, inferior parietal, occipital, and frontal cortices.
White matter density in arbitrary units by structural Magnetic Resonance Imaging pre-intervention, and immediately after the intervention White matter density at cortical and subcortical regions will be taken by structural MRI. The regions of interest include the cerebellum, basal ganglia, thalamus, hippocampus, inferior parietal cortex, occipital and frontal lobe.
Fractional anisotropy ranges from 0-1 derived from Diffusion Tensor Imaging pre-intervention, and immediately after the intervention The degree of anisotropy of water diffusion in white matter tracts will be derived from the diffusion tensor. The regions of interest include the cerebellum, basal ganglia, thalamus, hippocampus, inferior parietal cortex, occipital and frontal lobe.
Trial Locations
- Locations (1)
The Hong Kong Polytechnic University
🇭🇰Hong Kong, Hong Kong