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Background: This study aimed to compare trunk and lower limb muscle activity between healthy adults and older adults during the bird-dog exercise performed under visual occlusion conditions. Age-related declines in sensory integration and neuromuscular control may influence postural stabilization strategies, particularly during dynamic core exercises performed on unstable support surfaces. However, limited evidence exists regarding age-related differences in muscle activation patterns under visually constrained conditions. Methods: Thirty participants (15 adults, 15 older adults) performed the exercise for 20 s on an unstable surface under eyes-open and eyes-closed conditions. Each trial was maintained for 20 seconds and repeated three times with sufficient rest between trials. Surface electromyography was used to measure the activity of the rectus abdominis, external oblique, erector spinae, and gluteus maximus muscles. Electromyographic signals were normalized to maximal voluntary isometric contraction values for between-group comparisons. Results: The adult group showed significantly higher muscle activity in all the measured muscles compared to the older adult group (p<.05). Within-group analysis revealed that the gluteus maximus activity significantly increased under visual occlusion in the adult group, whereas rectus abdominis activity significantly increased in the older adult group (p<.05). Correlation analysis showed a significant positive correlation only in the rectus abdominis for the adult group, while the older adult group demonstrated significant positive correlations across all muscles. Conclusion: Adults primarily relied on selective muscle activation strategies to maintain stability, whereas older adults adopted a compensatory neuromuscular strategy characterized by simultaneous activation of multiple muscles. These findings demonstrate age-related differences in neuromuscular control during visually constrained core stabilization tasks and support the development of age-specific core stabilization training programs.