Stroboscopic visual interference combined with balance training improves the balance ability of older adults

Abstract

BACKGROUND: Numerous studies have indicated that stroboscopic visual interference combined with balance training can promote postural stability by reducing visual compensation in the central nervous system and increasing residual proprioceptive and vestibular input during training. OBJECTIVE: To clarify the effects of stroboscopic visual interference combined with balance training on improving balance ability of older adults by comparing the effects of balance training under different visual conditions. METHODS: Forty-three older adults were recruited and randomized into a normal balance training group (n=23) and a strobe vision training group (n=20). Among them, the balance training content was the same, and the training was conducted 3 times per week for 8 weeks. For the strobe vision training group, strobe glasses were worn during the balance training, and the strobe difficulty level (levels 1-8) was adjusted adaptively. Indicator tests were conducted at weeks 0, 4, 8, and 10 to assess the dynamic and static postural stability and the scores on the Berg Balance Scale of all subjects. RESULTS AND CONCLUSION: (1) Static postural stability: In the flat-surface eyes-closed single-leg stance test, both groups showed a significant time main effect (P < 0.001), but the group effect (P=0.530) and group×time interaction effect (P=0.780) were not significant. In the foam-surface eyes-closed single-leg stance test, both groups showed significant time (P < 0.001) and group (P=0.024) effects, but no group×time interaction effect (P=0.063). Compared with before training, both groups showed significant improvements in static postural stability after 8 weeks (P=0.034, P < 0.001) and 10 weeks (P=0.003, P < 0.001). (2) Dynamic postural stability: There was a significant group×time interaction effect (P < 0.001), while the main effects of group (Timed Up and Go and 3-m heel-to-toe walk: P=0.461, P=0.926) and time (P=0.120, P=0.937) were not statistically significant. Compared with before training, both groups showed significant improvements in dynamic postural stability after 4, 8, and 10 weeks of training (all P < 0.05). (3) Berg Balance Scale scores: There was a significant time effect (P < 0.001); group (P=0.420) and group×time (P=0.239) factors had no statistical significance on Berg Balance Scale scores. Compared with before training, both groups had higher Berg Balance Scale scores after 4 weeks (P=0.025), 8 weeks (P < 0.001), and 10 weeks (P=0.003). (4) It is suggested that both traditional balance training and strobe training can significantly improve the dynamic and static stability of older adults. Compared with traditional balance training, balance training based on stroboscopic visual interference can significantly improve the dynamic balance ability of older adults.

1. Introduction

Currently, the main means to prevent falls in older adults is to improve their balance ability through different intervention training methods [1-2]. For example, vestibular function training (such as ball yoga, suspension training) enhances vestibular adaptation through acceleration stimulation [3-5]; proprioceptive training (unstable support surface training, vibration training) strengthens neuromuscular control [6-7]; visual interference training (stroboscopic stimulation, eyes-open/closed training) improves multisensory integration ability [8-9]; lower limb resistance and aerobic exercise (Tai Chi, progressive resistance) maintains postural stability by enhancing muscle strength and coordination [10-11]. This study adopts stroboscopic visual interference training to improve the balance ability of older adults.

Stroboscopic visual interference training is a novel training technique that originated in the United States in the 19th century, which enhances multisensory integration and visual cognitive function through intermittent visual input restriction (such as stroboscopic glasses) [12]. Initially used to train athletes' competitive performance, this technique reduces visual dependence, prompting the brain to improve the processing efficiency of remaining visual information and activate neuroplasticity to strengthen the sensory reweighting of proprioceptive and vestibular systems, thereby improving visual-motor coordination, dynamic visual acuity, and motor reaction speed. Training methods mainly include adjusting the duty cycle, frequency, and training duration of stroboscopic glasses, combined with reaction, balance, and specific motor tasks, gradually increasing training difficulty [13]. In recent years, with in-depth research, this technique has been proven to not only effectively improve the body's motor reaction speed but also significantly improve dynamic balance ability. For example, SYMEONIDOU et al. [14] found that after treadmill walking training in healthy subjects, the dynamic balance improvement in the visual interference group was 78% greater than that in the normal vision group, and 61% of the training effect was retained after 2 weeks, while the control group retained only 5%. Wu Yihan et al. [15] and KIM et al. [13] respectively studied patients with chronic ankle instability and found that 4 weeks of stroboscopic visual interference combined with balance training significantly improved proprioception, ankle stability self-evaluation, and dynamic postural stability; after 6 weeks of intervention, ankle function and balance test scores also significantly improved. Domestic researchers have focused on young populations such as anterior cruciate ligament reconstruction patients, ankle instability patients, and healthy college students [16-21], with few studies focusing on older adults. CHEN's team [22] in 2021 used minimum spanning tree EEG connectome analysis to show that older adults (65.5±3.0 years) rely on visual input for balance.