Neural, Cognitive, and Biomechanical Determinants of Falls in Older Adults

N/ANot Yet RecruitingNCT07739056

University of Sharjah80 enrolled

Overview

The goal of this clinical trial with an embedded observational phase is to evaluate whether a phenotype-guided, personalized rehabilitation program can improve fall risk and underlying neural control mechanisms in older adults aged ≥65 years, including both high and low fall-risk individuals. The main questions it aims to answer are: Do older adults at high fall risk exhibit altered neural, neurocognitive, and biomechanical profiles compared with low/no fall-risk individuals? Does personalized rehabilitation guided by neurophysiological and neurocognitive profiles result in greater reductions in fall risk and improvements in motor control compared with conventional rehabilitation? Researchers will compare personalized phenotype-guided rehabilitation to conventional evidence-based fall-prevention exercise to determine whether targeted, mechanism-based intervention leads to superior clinical and mechanistic outcomes. Participants will: Undergo a comprehensive multimodal assessment including neurophysiological (EEG, EMG), neurocognitive (fNIRS, dual-task testing), and biomechanical (gait and balance) measures Be classified into fall-risk and neurophysiological control profiles based on assessment results (Phase 2 - high fall-risk participants only) be randomly assigned to either personalized rehabilitation or conventional rehabilitation Attend supervised exercise sessions 2-3 times per week for 8-12 weeks Complete gait, balance, and cognitive-motor assessments before and after the intervention Record falls prospectively using monthly fall diaries and follow-up monitoring over 3-6 months

Background: Falls among older adults are a leading cause of injury, disability, and loss of independence worldwide. Despite the availability of exercise-based and multifactorial interventions, their effectiveness remains inconsistent, partly because current approaches do not adequately address the underlying mechanisms of instability. Emerging evidence suggests that fall risk arises from complex interactions between neural, cognitive, and biomechanical systems, with substantial heterogeneity in control strategies across individuals. This study aims to develop and evaluate a mechanism-based framework that integrates these domains to improve fall-risk assessment and guide personalized rehabilitation. Objectives: The primary objectives are: (1) to compare neural, neurocognitive, and biomechanical determinants of fall risk between older adults with high and low fall risk; and (2) to evaluate whether a personalized rehabilitation program guided by individual neurophysiological and neurocognitive profiles leads to greater reductions in fall risk and improvements in motor control compared with conventional rehabilitation. Methods: This study adopts a two-phase multimodal design. Phase 1 is a cross-sectional causal-comparative study involving approximately 80 community-dwelling older adults aged 65 years and above, classified as high or low fall risk. Participants will undergo comprehensive assessment of neural control, neurocognitive load, and functional performance using electroencephalography and electromyography, functional near-infrared spectroscopy during dual-task conditions, and quantitative gait and balance analysis. Phase 2 is a pilot randomized controlled trial involving high fall-risk participants, who will be allocated to either a personalized rehabilitation program guided by individual neurophysiological and neurocognitive profiles or a conventional evidence-based fall-prevention program. Both groups will receive supervised training for 8-12 weeks. Primary outcomes include feasibility measures and prospective fall events over 3-6 months. Secondary outcomes include changes in neural control, cognitive-motor integration, and biomechanical stability. Discussion: This study proposes a novel phenotype-guided approach to fall prevention that targets the underlying neural control mechanisms rather than general physical impairments. By integrating multimodal assessments with personalized intervention, the study has the potential to improve the precision and effectiveness of rehabilitation strategies. Findings will provide important insights into the mechanisms of fall risk and inform the design of larger clinical trials and future clinical practice.

Interventions

Personalized Neurophysiological RehabilitationOTHER

The intervention targets underlying neural control mechanisms and is adapted based on identified control strategies (e.g., cortical-dominant, reflex-dominant, or integrated control). Intervention components may include: Task-specific balance and gait training under variable sensory conditions Dual-task training to improve cognitive-motor integration External focus and rhythm-based training to enhance movement automaticity Reaction-based and perturbation training to improve adaptability Progressive modulation of task complexity based on participant response Program details: Duration: 8-12 weeks Frequency: 2-3 supervised sessions per week Session length: 45-60 minutes The intervention is dynamically progressed based on neurophysiological and functional responses.

Conventional Fall-Prevention Exercise ProgramOTHER

The intervention focuses on general physical improvements rather than individualized neural mechanisms. Intervention components include: Balance training (static and dynamic postural control exercises) Lower-limb strengthening exercises (e.g., sit-to-stand, step-ups, resistance training) Gait and functional mobility training (walking, turning, obstacle negotiation) Flexibility and mobility exercises Education on fall prevention strategies Program details: Duration: 8-12 weeks Frequency: 2-3 supervised sessions per week Session length: 45-60 minutes Progression is based on

Eligibility

Sex: ALLMin age: 65 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * Participants must meet all of the following criteria: * Age ≥ 65 years * Community-dwelling * Ability to ambulate independently (with or without assistive device) * Ability to understand instructions and provide informed consent Participants will be stratified into fall-risk categories based on established criteria: * High fall risk: history of ≥1 fall in the previous 12 months and/or impaired functional performance (e.g., TUG \> 13.5 s or BBS ≤49) * Low/no fall risk: no falls and preserved functional mobility These criteria are consistent with previously published fall-prevention trials. Exclusion Criteria: * Participants will be excluded if they have: * Neurological conditions affecting gait or balance (e.g., stroke, Parkinson's disease) * Severe musculoskeletal disorders limiting mobility * Severe cognitive impairment (e.g., inability to follow instructions or MoCA \< 18) * Uncontrolled cardiovascular or metabolic conditions * Current participation in structured rehabilitation programs * Contraindications to EEG, EMG, or fNIRS measurements

Outcomes

Primary Outcomes

Recruitment Rate

Recruitment feasibility will be assessed by calculating the average number of participants enrolled per month during the recruitment period. Unit of Measure: Participants/month

Time frame: From initiation of recruitment until enrollment of the final participant, anticipated period of (12 months)

Participant Attrition Rate

Participant retention will be assessed by calculating the proportion of enrolled participants who withdraw or are lost to follow-up before completion of the final study assessment. Unit of Measure: Percentage (%)

Time frame: From enrollment through the 3-6-month follow-up.

Supervised Intervention Attendance Rate

Intervention adherence will be assessed by calculating the percentage of prescribed supervised intervention sessions attended by each participant. Unit of Measure: Percentage (%)

Time frame: Throughout the 8-12-week intervention period.

Participant Satisfaction with the Intervention

Acceptability of the intervention will be assessed using a participant satisfaction questionnaire ( PSQ-18) administered after completion of the intervention. The total satisfaction score will be reported, with higher scores indicating greater participant satisfaction. Unit of Measure: Questionnaire total score

Time frame: Immediately after completion of the 8-12-week intervention.

Proportion of Participants with Usable Neurophysiological Data

Data quality will be assessed by calculating the proportion of participants with complete, artifact-free, and analyzable neurophysiological recordings (EEG, EMG, and fNIRS) according to predefined signal-quality criteria. Unit of Measure: Percentage (%)

Time frame: Baseline and immediately after completion of the 8-12-week intervention

Proportion of Participants with Complete Biomechanical Data

Data completeness will be assessed by calculating the proportion of participants with complete and analyzable biomechanical recordings, including gait and balance measures, according to predefined quality-control criteria. Unit of Measure: Percentage (%)

Time frame: Baseline, immediately after completion of the 8-12-week intervention, and at the 3-6-month follow-up.

Secondary Outcomes

Number of Falls per Participant

Description The total number of falls experienced by each participant during the follow-up period will be prospectively recorded using monthly fall diaries, structured telephone follow-up, and caregiver confirmation when applicable. A fall is defined as "an unexpected event in which the participant comes to rest on the ground, floor, or lower level." Unit of Measure Number of falls

Time frame: During the 3- to 6-month follow-up period after completion of the intervention.

Time to First Fall

Time from completion of the intervention to the first prospectively recorded fall will be measured using monthly fall diaries, structured telephone follow-up, and caregiver confirmation when applicable. A fall is defined as "an unexpected event in which the participant comes to rest on the ground, floor, or lower level." Unit of Measure Days (or Months, depending on your planned statistical analysis)

Time frame: During the 3- to 6-month follow-up period after completion of the intervention.

Neurophysiological Outcomes (Corticomuscular Coherence (CMC))

Primary metric: ΔCMCβ = CMCFoam EC - CMCFirm EO Outcomes: * Change in ΔCMCβ from baseline to post-intervention * Normalization of task-dependent cortical modulation Interpretation: Reflects changes in cortical involvement and neural efficiency in postural control.

Time frame: Phase 1 at baseline, post phase 2 intervention 8-12 weeks, and follow up 3-6 month

Neurophysiological Outcomes (Intermuscular Coherence (IMC))

Coordination of shared neural input between muscles assessed using intermuscular coherence. Primary metric: ΔIMCLF = IMCFoam EC - IMCFirm EO Outcomes: * Change in low-frequency IMC modulation * Improvement in coordination patterns Interpretation: Reflects reorganization of subcortical and intermuscular coordination mechanisms.

Time frame: Phase 1 at baseline, post phase 2 intervention 8-12 weeks, and follow up 3-6 month

Change in Prefrontal Oxygenated Hemoglobin Concentration During Dual-Task Walking

Prefrontal cortical activation will be assessed using functional near-infrared spectroscopy. Oxygenated hemoglobin concentration will be recorded during single-task walking and dual-task walking. The outcome will be the dual-task-related change in oxygenated hemoglobin concentration, calculated as the mean oxygenated hemoglobin concentration during dual-task walking minus the mean oxygenated hemoglobin concentration during single-task walking. Results will be reported in micromoles per liter (µmol/L). A reduction in excessive dual-task-related prefrontal oxygenation after the intervention will be interpreted as improved neural efficiency, provided that walking and cognitive-task performance are maintained or improved.