Electromyography Biofeedback Balance Training In Aging: Effects on Spinal Reflexes and Balance Control

Abstract

Declines in balance lead to an increased fall risk among older adults, emphasizing the crucial need for interventions which help maintain postural control and independence. EMG-BF provides a unique approach by delivering real-time sensory feedback based on the muscle activation of users. This research investigated the effects of a one-month EMG-BF training program composed of 16 training sessions on balance performance, spinal reflex excitability, and balance confidence among healthy older adults. Thirty-three participants were randomly assigned to the control or intervention group, and randomization was stratified based on age and sex. The BTrackS balance board was used to assess postural sway and to perform limits of stability (LOS) testing. Hoffmann’s Reflex (H-reflex) measured spinal reflex excitability and balance confidence was assessed using the Activities-Specific Balance Confidence (ABC) Scale. Results demonstrated no significant differences between the intervention and control group for any of the dependent measures. For both groups, sway path length had a significant increase between baseline and the follow-up assessment, and H-reflex amplitude for the left leg decreased significantly over time. H-reflex amplitude was significantly larger for the right leg, in comparison to the left, and this may be due to foot dominance since the majority of the participants were right-foot dominant. A positive correlation was found between LOS surface area and balance confidence. EMG-BF did not lead to improvements in balance or spinal reflex outcomes regardless of the passage of time. An explanation for this could be that the participants had low fall risk and high balance confidence at baseline. The EMG-BF training protocol may also have not been challenging enough compared to alternative balance interventions. Overall, these findings emphasize the importance of researching future EMG-BF protocols. These future protocols should involve progressively challenging tasks to promote effectiveness in older adults with greater fall risk.protocols should involve progressively challenging tasks to promote effectiveness in older adults with greater fall risk.