Neurophysiological Changes After Perturbation-based Training in Older Adults
NCT Number: NCT06573658
Status: RECRUITING
Study Type: INTERVENTIONAL
Phases: NA
Conditions: Healthy Subjects|Postural Balance|Falling
Interventions: BEHAVIORAL: Perturbation-based balance training (PBT)|BEHAVIORAL: Active control (control)
Sponsor: The Hong Kong Polytechnic University
Sex: ALL
Age: ADULT, OLDER_ADULT
Enrollment: 88
Study Design: Allocation: RANDOMIZED|Intervention Model: PARALLEL|Masking: DOUBLE (INVESTIGATOR, OUTCOMES_ASSESSOR)|Primary Purpose: SUPPORTIVE_CARE
Start Date: 2024-04-18
Completion Date: 2026-10-14
Locations: The Hong Kong Polytechnic University, Hong Kong, Hong Kong

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.

Primary Outcome Measures: Gray matter density in arbitrary units by structural Magnetic Resonance Imaging, 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., pre-intervention, and immediately after the intervention|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, 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., pre-intervention, and immediately after the intervention
Secondary Outcome Measures: Postural stability, 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., pre-intervention, immediately after the intervention, 1 week after intervention and 4 months after intervention|Number of laboratory-falls, 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., pre-intervention, immediately after the intervention, 1 week after intervention and 4 months after intervention|Number of real-life-falls, 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., 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.|Step time of the recovery steps in milliseconds (ms), 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., pre-intervention, immediately after the intervention, 1 week after intervention and 4 months after intervention|Step length of the recovery steps in millimeters (mm), 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., pre-intervention, immediately after the intervention, 1 week after intervention and 4 months after intervention|Trunk angle, 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., pre-intervention, immediately after the intervention, 1 week after intervention and 4 months after intervention|Hip height in millimeters (mm), 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., pre-intervention, immediately after the intervention, 1 week after intervention and 4 months after intervention|Responsive postural adjustment upon translation, 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., pre-intervention, immediately after the intervention, 1 week after intervention and 4 months after intervention|Responsive postural adjustment upon tilting, 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., pre-intervention, immediately after the intervention, 1 week after intervention and 4 months after intervention|Muscle activation onset latency in milliseconds, Muscle latency will be collected from trunk and leg muscles using electromyography., pre-intervention, immediately after the intervention, 1 week after intervention and 4 months after intervention|Balance confidence, 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., pre-intervention, immediately after the intervention, 1 week after intervention and 4 months after intervention, and at the last prospective fall follow-up|Cognitive flexibility and executive function, Cognitive flexibility and executive function assessed by Trial Making Tests A and B (in the unit of seconds), pre-intervention, immediately after the intervention, 1 week after intervention, and 4 months after intervention|Functional lower body strength, Functional lower body strength will be assessed by Five-time Sit to Stand Test (in the unit of seconds), pre-intervention, immediately after the intervention, 1 week after intervention, and 4 months after intervention|Dynamic balance, Dynamic balance will be assessed by Alternate Step Test (in the unit of seconds), pre-intervention, immediately after the intervention, 1 week after intervention, and 4 months after intervention|Mobility, Mobility will be assessed by Timed Up and Go test (in the unit of seconds)., pre-intervention, immediately after the intervention, 1 week after intervention, and 4 months after intervention|White matter density in arbitrary units by structural Magnetic Resonance Imaging, 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., pre-intervention, and immediately after the intervention|Gray matter volume in cubic millimeters (mm³) by structural Magnetic Resonance Imaging (MRI), 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., pre-intervention, and immediately after the intervention|White matter volume in cubic millimeters (mm³) by structural Magnetic Resonance Imaging (MRI), 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., pre-intervention, and immediately after the intervention|Cortical thickness in mm measured by structural Magnetic Resonance Imaging, Cortical thickness in mm measured by structural MRI. The regions of interest include the cerebellar, inferior parietal, occipital, and frontal cortices., pre-intervention, and immediately after the intervention|Fractional anisotropy ranges from 0-1 derived from Diffusion Tensor Imaging, 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., pre-intervention, and immediately after the intervention|Mean diffusivity measures in mm²/s by Diffusion Tensor Imaging, 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., pre-intervention, and immediately after the intervention