تأثیر تمرینات تعادلی با محرک عصبی-بصری همراه با وظایف شناختی بر تعادل پویا، ترس از افتادن، کیفیت زندگی و عملکرد سالمندان

Introduction

Aging is a multifaceted process characterized by physiological changes profoundly impacting sensory-motor and cognitive systems in older adults. These alterations manifest as balance impairments, heightened fall risk, and secondary consequences like fear of falling and diminished quality of life (QoL). Falls pose a major public health issue for those aged 65+, with one-third experiencing at least one annually, escalating with age. Psychologically, falls trigger fear of falling—a persistent dread leading to activity restrictions, mobility decline, isolation, and functional deterioration.

Balance relies on multisensory integration of visual, vestibular, and proprioceptive inputs. In older adults, age-related declines disrupt this: visual acuity and peripheral vision weaken, contrast sensitivity drops, limiting compensatory roles; vestibular hair cell loss and otolith atrophy impair head movement and orientation; proprioceptive mechanoreceptor reductions erode body awareness and perturbation responses (9, 10). These sensory issues compound with musculoskeletal changes—lower extremity weakness, joint stiffness, delayed reactions—worsening postural sway and dynamic instability (11, 12).

Executive cognitive functions (divided attention, working memory, flexibility, processing speed) are crucial for balance, particularly in dual-task real-life scenarios. Aging-related cognitive decline overloads attentional resources during locomotion, increasing fall risk. Modern rehabilitation integrates physical exercises with sensory-cognitive stimuli to leverage neuroplasticity. Stroboscopic glasses intermittently occlude vision (e.g., 0.5-second cycles at 1 Hz), inducing perturbations that promote non-visual reliance and sensory reweighting, enhancing postural adaptability. Dual-task training pairs motor and cognitive demands, simulating real-life scenarios to boost balance, reduce fall risk, and ease fear of falling (13, 15).

Though traditional balance exercises, athlete-focused stroboscopic training, and standalone dual-tasks show benefits, few examine their combination in older adults, often overlooking holistic outcomes like fear of falling and QoL. This RCT fills this void by assessing stroboscopic balance training plus cognitive tasks on dynamic balance, fear of falling, QoL, and functional performance in community-dwelling adults aged 60-75. The hypothesis anticipates superior gains in the combined group versus stroboscopic alone or controls.

Methods

This quasi-experimental study employed a pretest-posttest design with a control group. The population included community-dwelling older adults in Karaj, Iran, aged 60-75 years. Inclusion criteria: independent ambulation without assistive devices, no severe neuromuscular/musculoskeletal disorders, no lower-limb surgery in the prior six months, and no balance-affecting medications. Exclusion: acute injuries/illnesses during intervention, >3 missed sessions, or consent withdrawal. Sample size: 45 participants (15/group), based on prior studies, with 80% power, α=0.05, and 20% attrition.

Following informed consent, participants were conveniently assigned to three groups: (1) stroboscopic balance training with cognitive tasks (ST+CT), (2) stroboscopic balance training without cognitive tasks (ST), and (3) control (no intervention). Baseline demographics were homogeneous (no differences in age, height, weight, BMI; Table 1).

Pre- and post-intervention assessments included: dynamic balance via Timed Up and Go (TUG) test (chair rise, 3-m walk/return/sit; mean of two trials); fear of falling via 16-item Falls Efficacy Scale-International (FES-I; 4-point Likert, 16-64 scores; higher=greater fear); QoL via 24-item WHOQOL-OLD (six domains: sensory abilities, autonomy, social participation, death attitudes, intimacy, prospects; 5-point Likert; higher=better); functional performance via Functional Reach (FR) test (max forward reach without foot shift; higher=better stability) .

ST+CT and ST followed Chen et al.'s (2025) protocol: barefoot on wooden stabilometer (≤20° tilt), 45-s trials (thrice per condition: full vs. stroboscopic vision at 1 Hz, 50% feedback reduction), 3-min rests; thrice weekly for 6 weeks (18 sessions), randomized order to reduce fatigue. ST+CT added cognitive tasks: arithmetic (serial subtractions), working memory (recall 5-7 items), verbal fluency (category naming), selective attention (Stroop-like), decision-making (date calculations); progressive difficulty, rotated for engagement .

Analysis used SPSS v27 (α=0.05). Shapiro-Wilk verified normality; Levene's, homogeneity; parametric tests otherwise. Mixed ANOVA tested time (pre/post) × group interactions, Tukey post-hoc for significance, paired t-tests for within-group changes. Partial eta-squared (η²_p) effect sizes followed Cohen (0.01 small, 0.06 medium, 0.14 large).

Results

Demographics showed no baseline intergroup differences (p>0.05). Mixed ANOVA revealed significant time × group interactions across outcomes (p<0.001).

For dynamic balance, ST+CT reduced TUG time from 13.8 ± 2.9s to 10.7±2.3s (t=8.2, P<0.001; η²p= 0.32), outperforming ST (13.5 ±3.1s to 11.2±2.8s; P = 0.02), and control (13.2±2.8s to 12.9 ±3.0s; P = 0.70). between-group: P <0.001).

Fear of falling decreased in ST+CT (FES-I: 28.5 ±7.2 to 21.3 ±5.3; t=6.5, p<0.001; η²p =0.25), more than ST (27.8 ± 6.9 to 24.6 ± 6.5; P =0.04) and control (28.2 ± 7.5 to 27.9 ± 7.3; P =0.92; between-group: P <0.005).

QoL improved in ST+CT (52.9±8.7 to 61.5±7.8; t=5.9, p<0.02; η²p =0.34), exceeding ST (53.1± 8.1 to 57.2± 5.3; P =0.02) and control (52.8± 8.2 to 52.9± 5.5; P = 0.84; between-group: P <0.001).

Functional performance advanced in ST+CT (FR: 24.8± 5.3cm to 31.2±4.5cm; t= 7.1, P <0.001; η²p= 0.38), surpassing ST (25.2±5.5cm to 28.1±4.4cm; P =0.03) and control (24.5± 5.7cm to 24.6±5.3cm; P= 0.64; between-group: P <0.001).

Overall, ST+CT yielded medium-to-large effects, underscoring cognitive integration's superiority.

Conclusion

This study confirms that stroboscopic balance training augmented by cognitive tasks significantly enhances dynamic balance, reduces fear of falling, elevates QoL, and bolsters functional performance in older adults, outperforming isolated training. These results align with meta-analyses on dual-task interventions, which yield small-to-moderate cognitive gains and medium-to-large motor benefits via neuroplasticity reorganizing neural pathways through concurrent demands .

TUG improvements in ST+CT reflect enhanced postural control and gait efficiency, driven by dual-task attentional allocation, automated motor patterns per dual-process theory, and stroboscopic perturbations strengthening predictive/feedback mechanisms. Fear reduction aligns with Bandura's self-efficacy theory: progressive successes build confidence, disrupting fear-avoidance cycles and modulating amygdala activity via cognitive restructuring.

QoL gains stem from restored autonomy and social engagement under the ICF model, as better balance enables daily activities, alleviating depression and isolation. FR improvements, with the largest effect, highlight real-world transfer by simulating ecological dual-tasks and desirable difficulty in motor learning.

Limitations include short-term follow-up and unmonitored confounders (e.g., daily activity). Future studies should incorporate long-term tracking, neuroimaging (fMRI/EEG), and diverse populations.

Integrating cognitive tasks with stroboscopic training offers a superior, neuroplasticity-driven intervention, enhancing balance, mitigating fall fear, boosting QoL, and optimizing performance. Clinicians should prioritize dual-task protocols in fall prevention to promote independence.

Footnotes

Funding: This study received no financial support from governmental centers or institutions.

Authors’ contribution: Study concept and design: A.A, S.S; Analysis and interpretation of data: A.A, S.S; Drafting of the manuscript: A.A; Critical revision of the manuscript for important intellectual content: S.S; Statistical analysis:A.A

Conflict of interest: The authors declare no conflicts of interest.

Acknowledgments: We extend our sincere gratitude to all individuals who assisted us in this endeavor.