The age distribution of the world's population is constantly changing, with a global trend of increasing numbers of older people and a simultaneous decrease in the number of young people 1. This shift has captured the attention of the scientific community, particularly concerning aging and, more specifically, successful aging. Consequently, numerous interventions have been developed to improve the physical and psychosocial well-being of the elderly 2. The global prevalence of falls related to geriatric imbalance is high, affecting approximately one in three elderly individuals (over 65 years) annually. These falls result in injuries, disabilities, loss of independence, and even fatalities among the elderly population 3. Regular physical activity has a positive impact on the physical health of the elderly, offering a wide range of benefits and serving as both a preventive measure and a rehabilitative approach to addressing the numerous health risks faced by this age group. Functional assessment, which includes standard tests of physical performance like walking speed, standing balance, and strength, plays a crucial role in the clinical examination of the elderly population, as it assists in evaluating their physical capabilities and has been shown to predict outcomes such as falls and death 4, 5. Functional measures of balance, such as the Timed up and Go test, are widely used due to their low cost and ease of administration, and numerous different functional measures are available. However, there is no guidance on which combination comprehensively assesses balance 6, 7. Furthermore, a systematic review conducted by McMullan et al. revealed that out of 30 studies, only one included the functional measures necessary to comprehensively assess balance across all body systems 8. Maintaining a standing position and balance requires the central integration of sensory systems and the appropriate motor output from the neuromuscular system to maintain the center of pressure within the support base. Unilateral peripheral vestibular disorder (UPVD) reduces the stability of this condition 9. International guidelines advocate for balance training, known as vestibular rehabilitation, as a primary component of treatment. However, its effectiveness is often constrained 10. Given the circumstances and inadequate response to standalone balance training, advanced training approaches have been devised 11. Based on the identified function, immediate visual, auditory, electrotactile, and vibration biofeedback can be provided to enhance somatosensory input and augment balance control. Previous studies demonstrate that biofeedback devices effectively improve static and dynamic balance in both healthy elderly individuals and patients with balance and walking disorders 12.
Neurofeedback, a form of biofeedback, educates subjects in self-regulation of brain functions by measuring brain waves and delivering feedback signals. It is not a novel concept; researchers have studied it for several decades. Neurofeedback enables subjects to consciously manipulate their brain waves 13. During neurofeedback therapy, electroencephalography (EEG) is recorded, and its various components are extracted and presented to subjects via an online feedback loop in the form of audio, video, or a combination thereof. Positive or negative feedback is provided for favorable or unfavorable brain activities, respectively. For instance, subjects strive to enhance brain patterns based on training-induced alterations and can assess their progress toward achieving desired performance levels 14, 15.
It is widely believed that balance disorders constitute one of the primary causes of falls among the elderly. These disorders are linked to the natural aging process and result in the degradation of integration and processing of information from the vestibular, somatosensory, and visual systems 16. Consequently, there is an escalation in postural fluctuations, which are among the factors influencing balance. Effective control of balance in both static and dynamic activities is pivotal for the daily functioning of the elderly 16. It is evident that balance assessment is imperative not only for gauging the risk of falling but also for pinpointing which balance factors exert the most significant influence on fall risk 16. On the other hand, balance exercises focus on isolating and challenging the sensory, visual, and vestibular systems 17. People in old age undergo changes in brain structure that diminish the functionality of the body's movement and sensory systems. Various intervention strategies have been suggested to prevent and ameliorate brain dysfunction in the elderly. Somatosensory training, which involves engaging the sensory and motor functions of the brain, emerges as one of the most accessible approaches. Specifically, somatosensory training relies on the central nervous system's capacity to "re-weight" sensory inputs, utilizing a functional approach 18. Neurofeedback, recognized as a complementary and alternative treatment for numerous brain disorders, is hypothesized to integrate somatosensory exercises in real-time, acting as an additional input to complement other sensory information within the central nervous system 19. In individuals with balance deficits, such as healthy elderly individuals, various sensory modalities (including vibratory, visual, auditory, electrotactile, and multimodal approaches) have demonstrated efficacy in enhancing real-time balance performance. These modalities have been shown to reduce body sway during static, dynamic, and standing tasks 20–22. Given the frequently catastrophic and debilitating outcomes of fall-related injuries, balance constitutes a significant concern in the elderly demographic. Structural and functional deterioration of the sensorimotor system accompanies aging, potentially exacerbating postural instability in this population. Another critical challenge in this domain pertains to the assessment of balance and its intricacies. Contemporary balance theory posits that a thorough evaluation of balance should encompass assessments of neuromuscular, cognitive, and somatosensory functions to ensure accurate assessment and effective mitigation of falls 6. Therefore, the present study was conducted to investigate the effects of neurofeedback, somatosensory exercises, and their combination on the balance and physical performance of healthy elderly individuals.